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Adequate illumination of the larynx is needed during laryngoscopy to facilitate tracheal intubation. The International Organization for Standardization (ISO) has established a minimum light intensity for direct laryngoscopy (DL) of over 500 lux for at least ten minutes, but no such standard exists for Macintosh geometry videolaryngoscope (Mac-VL) blades, which allow for both direct or indirect (videoscopic) viewing of the larynx. Using in situ bench and in vitro testing in a human cadaver, we determined illumination and luminance values delivered by various Mac-VLs and compared these with published minimum lighting benchmarks as well as a reference direct laryngoscope.We tested six Mac-VLs (i-view™, McGRATH™ MAC, GlideScope® Spectrum™ [single-use] DVM S4, GlideScope® Titanium [reusable] Mac T4, C-MAC® S [single-use] Macintosh #4, C-MAC® [reusable] Macintosh #4) together with one direct laryngoscope (Heine LED). Each laryngoscope was assessed with three measurements, as follows: part 1: illuminance (lux) was measured in situ using a purpose-designed benchtop light intensity measurement apparatus; part 2: luminance (light reflected back to the eye) was measured (in candela mIlluminance and luminance varied significantly among the Mac-VLs. Mean (standard devitation) illuminance among the six tested Mac-VLs ranged from 117 (11) to 2,626 (42) lux in the measurement apparatus and from 228 (11) to 2,900 (374) lux by the surgically implanted light meter in the cadaver. All values were less than the reference Heine direct laryngoscope and some fell below the published ISO standard of 500 lux for DL. Luminance testing by spot meter had a similarly wide range, varying from 3.78 (0.60) to 49.1 (10.4) cd·mOur results indicate that illuminance and luminance provided by Mac-VLs used for direct laryngeal viewing varies substantially between devices, with some falling below standards previously suggested as the minimum required for DL. While this may have no implications for the quality of image visible on a device's video monitor, the clinician should be aware that when Mac-VLs are used for direct viewing of the larynx, lighting may not be optimal. This might adversely affect ease or success of tracheal intubation.RéSUMé: CONTEXTE: L’éclairage adéquat du larynx est nécessaire pendant la laryngoscopie pour faciliter l’intubation trachéale. Pour la laryngoscopie directe (LD), l’Organisation internationale de normalisation (ISO) a établi une intensité lumineuse minimale de plus de 500 lux pendant au moins dix minutes. Toutefois, il n’existe aucune norme de ce type pour les lames de vidéolaryngoscope à géométrie Macintosh (VL-Mac), qui permettent une visualisation directe ou indirecte (vidéoscopique) du larynx. Par des études en laboratoire et in vitro sur un cadavre humain, nous avons déterminé les valeurs d’éclairage et de luminance fournies par divers VL-Mac et les avons comparées aux valeurs repères d’éclairage minimal publiées ainsi qu’aux valeurs obtenues avec un laryngoscope direct de référence. MéTHODE: Nous avons testé six VL-Mac (i-view™, McGRATH™ MAC, GlideScope® Spectrum™ [à usage unique] DVM S4, GlideScope® Titanium [réutilisable] Mac T4, C-MAC® S [à usage unique] Macintosh #4, et C-MAC® [réutilisable] Macintosh #4) ainsi qu’un laryngoscope direct (Heine LED). Chaque laryngoscope a été évalué avec trois mesures, comme suit : partie 1: l’éclairage (lux) a été mesuré in situ à l’aide d’un appareil spécialement conçu de mesure de l’intensité lumineuse en laboratoire; partie 2 : la luminance (lumière réfléchie vers l’œil) a été mesurée (en candela m-2 [cd·m-2]) pendant la vidéolaryngoscopie (VL) et la LD sur un cadavre humain, à l’aide d’un posemètre pointé vers la commissure interaryténoïdienne; partie 3: l’éclairage (lux) a été mesuré pendant la VL et la LD sur un cadavre humain à l’aide d’un photomètre implanté chirurgicalement juste en amont des cordes vocales. RéSULTATS: L’éclairage et la luminance variaient considérablement entre les VL-Mac. L’éclairage moyen (écart type) parmi les six VL-Mac testés variait de 117 (11) à 2626 (42) lux avec l’appareil de mesure, et de 228 (11) à 2900 (374) lux lorsque mesuré par le photomètre implanté chirurgicalement dans le cadavre. Toutes les valeurs étaient inférieures au laryngoscope direct Heine de référence, et certaines étaient inférieures à la norme ISO publiée de 500 lux pour la LD. Les essais de luminance par posemètre ont rapporté une plage tout aussi large, variant de 3,78 (0,60) à 49,1 (10,4) cd·m-2, certains VL-Mac offrant moins de luminance que le laryngoscope direct Heine de référence. CONCLUSION: Nos résultats indiquent que l’éclairage et la luminance fournis par les VL-Mac utilisés pour la visualisation directe du larynx varient considérablement d’un appareil à l’autre, certains tombant en dessous des normes précédemment suggérées comme minimalement requises pour la LD. Bien que cela puisse n’avoir aucune incidence sur la qualité de l’image visible sur le moniteur vidéo d’un appareil, le clinicien doit être conscient que lorsqu’un VL-Mac est utilisé pour la visualisation directe du larynx, l’éclairage pourrait ne pas être optimal. Cela pourrait nuire à la facilité ou au succès de l’intubation trachéale.

Purpose To investigate the feasibility and practicality of ultraviolet (UV) germicidal irradiation of the inner bore of a computed tomography (CT) gantry as a means of viral decontamination. Method A UV lamp (PADNUT 38 W, 253 nm UV‐C light tube) and UV‐C dosimeter (GENERAL UV‐C Digital Light Meter No. UV512C) were used to measure irradiance throughout the inner bore of a CT scanner gantry. Irradiance (units μW/cm2) was related to the time required to achieve 6‐log viral kill (10−6 survival fraction). Results A warm‐up time of ~120 s was required for the lamp to reach stable irradiance. Irradiance at the scan plane (z = 0 cm) of the CT scanner was 580.9 μW/cm2, reducing to ~350 μW/cm2 at z = ±20 cm toward the front or back of the gantry. The angular distribution of irradiation was uniform within 10% coefficient of variation. A conservative estimate suggests at least 6‐log kill (survival fraction ≤ 10−6) of viral RNA within ±20 cm of the scan plane with an irradiation time of 120 s from cold start. More conservatively, running the lamp for 180 s (3 min) or 300 s (5 min) from cold start is estimated to yield survival fraction <

This study tested if the type of light meter device can influence the relationships between plant canopy height with light interception (LI) and leaf area index (LAI), in different types of warm-season grasses. LI and LAI were measured using Digital Plant Canopy Imager model 120 (CI-120) (CID Bio-science®) and Plant Canopy Analyzer LAI-2000 (LI-COR®). Seven warm-season grasses were evaluated Urochloa decumbens (Stapf) R.D. Webster.; Urochloa ruziziensis (R.Germ. & C.M. Evrard) Crins; Megathyrsus maximum (Jacq.) B.K. Simon & S.W.L. Jacobs cv. Tanzânia, M. maximum (Jacq.) B.K. Simon & S.W.L. Jacobs cv. Mombaca, Pennisetum purpureum Schumach. cv. Mott, P. purpureum Schumach. cv. Taiwan A-146 2.37, P. purpureum Schumach. cv. Roxo. There was a predominance of non-significant correlations between canopy height with LI and LAI measured using CI-120 ( p > 0.05). Moderate to strong correlations were obtained between canopy height with LI and LAI measured using LAI-2000 (p < 0.01). LAI-2000 was found to be a potential device for modelling relationships between canopy height with LI/LAI in warm-season grasses. The findings of this trial indicate that the type of light meter device has a strong influence on the correlations between canopy height and light interception in warm-season grasses.

The study population was all patients in the ICU. Samples were 170 patients in the ICU according to the inclusion criteria. Independent variables are room temperature, lighting level, and noise level. The dependent variable is the level of pain. The research instruments were CPOT, lux meter, and light meter. Data were collected using observation sheets and analyzed using regression. Result of research showed that the pain scale based on CPOT most respondents had Moderate pain as many as 43 respondents (50.6%), that the lighting environment (40.22 ± 41.1), noise (60.23 ± 8.5), and room temperature (26.76 ± 1.2) were not directly related to the patient's pain level. Environments factors in this study were not directly related to the pain level. there may be other factors that cause the patient's pain to determine the action, prognosis, and use of a mechanical ventilator

This work provides an approach for simplifying and teaching of the confusing topic of Polarisation of light and relating Malus’s Law. Teaching Polarisation and the Malus’s Law are modestly achieved by means of smartphones with a convenient light meter application. The apparatus is designed so that the polarizer, the analyser, the laser light source and the smartphone are precisely aligned on a rail. During the performance, the angle of the analyser is basically varied with respect to the polariser and the transmitted light intensity is measured by the light meter application. The results clearly show that the transmitted light intensity is directly proportional to the squared polarization angle. The approach surely provides accessibility for physics teachers and would help students to learn and internalize Polarisation and relating Malus’s Law in a better manner.

MHSC (Occupational Hygiene), North-West University, Potchefstroom Campus In the field of occupational hygiene, light and the use of different lighting types have become fundamental control measures in reducing risks to health and safety while at the same time promoting increased productivity within the workplace. Illuminance meters are used in surveys to quantify the amount of light illuminating an object, surface, or general workplace to determine if illumination in the workplace complies with regulations and standards. Accurate illuminance measurement requires important considerations, such as the calibration conditions of illuminance meters, the spectral response of illuminance meters and the specific light source being measured. The general aim of this study was to measure and compare illuminance values obtained from the Goldilux auto-ranging light meter (GL) (MIT, South Africa), Goldilux-LED auto-ranging light meter (GL-LED) (MIT, South Africa) and the Konica Minolta CL-70f illuminance meter (KM CL- 70f) (Konica Minolta, Japan) under controlled laboratory conditions. The objectives of this study were: (i) to measure and compare the illuminance levels of halogen incandescent lamps (hICLs), compact fluorescent lamps (CFLs) and light emitting diodes (LEDs) using the GL (MIT, South Africa), the GL-LED (MIT, South Africa) and the KM CL-70f (Konica Minolta, Japan); (ii) to measure and compare the illuminance levels of low-, medium-, and high-output hICLs, CFLs and LEDs, and (iii) to measure the colour correlated temperatures (CCTs) and spectral wavelengths of each of the above-mentioned light sources with the KM CL-70f illuminance meter (Konica Minolta, Japan). The GL, GL-LED, and KM CL-70f were used to measure low-, medium-, and high-output hICLs, CFLs and LEDs precisely one metre away from the selected lamps under laboratory conditions. Background illumination in the test facility was 0 lux. Lamps were individually measured for two minutes, or until the values on the illuminance meter had stabilised. Lamp measurements were repeated three times (n=9 per lamp). Results of the GL, GL-LED, and KM CL-70f were similar when measuring low- and mediumoutput hICLs. Statistically significant differences in illuminance values were observed when measuring high-output hICLs and all CFLs and LEDs. The degree to which illuminance values differed, increased when measuring lamps with higher outputs. Spectral wavelength measurements indicate that CFLs and LEDs have entirely different spectral qualities in comparison to the traditional ICL and hICLs. To achieve accurate measurements of modern lamps, such as CFLs and LEDs, illuminance meters having a spectral response capable of measuring the entire visible spectrum should be used. Furthermore, due to the differences in spectral wavelength qualities of lamps, illuminance meters should be calibrated to measure modern lamp types such as CFLs and LEDs. There is a need for the development of regulations and standards that define which qualities of illuminance meters are required for accurately measuring light within the workplace. Currently, there is limited information considering the minimum required quality indices such as the spectral distribution qualities or the spectral mismatch factor that illuminance meters should conform to when measuring light in the workplace. The need for development of regulations and standards, as well as the application of the GL, GL-LED and KM CL-70f in the workplace were recommended. A study limitation and future studies were also discussed. Masters

The piping systems used for the transportation of liquids and gases in power stations, petroleum petrochemical facilities, and chemical plants are significantly impacted by corrosive processes. One of the most destructive forms of corrosion is pitting corrosion, which produces holes on piping metal surfaces. Monitoring pit depth is necessary in order to prevent leakage in the piping system, especially during operation. However, measuring pit depth as a part of periodical inspections is complicated since the pit depth on the outside wall of a pipe may vary. Non-destructive testing (NDT) methods such as ultrasonic, liquid penetrants, and magnetic particles are used to detect defects in industrial components; however, they first require the removal of insulation and the shutdown of the pipe system. Another alternative NDT technique, tangential radiography technique (TRT), offers a solution to this problem as tests can be conducted without removing piping insulation, allowing testing while the piping system is online. In this study, we tested TRT using an X-ray radiation source, which has good controllability (i.e., intensity and exposure time) and a lower impact on the human body than do γ-ray sources. We focused on the comparison of film density measurements using a density meter and a light meter. The magnification of pit diameter was used to obtain an equation for small-diameter pipes (i.e., diameter of less than 50 mm). The working voltage was varied (200, 230, and 260 kV) in order to generate appropriate X-ray energies to measure various pit depth (20, 40, and 60%, receptively) of a stepped steel pipe specimen. Film density measurements using the density and light meters showed similar results; however, the film density result using the density meter was more accurate. All tangential side edges of the specimen burned off for film densities above 3.5. Degrees of magnification (1.0123, 1.0254, and 1.0379) varied as a function of distance from the midpoint of the X-ray target (30, 60, or 90 mm, respectively). Using the results, a linear equation with three variables was obtained to determine the actual diameter of pitting: 0.000385436a + 0.038350128b + 0.000467083c = d; where the actual diameter = film diameter/d. High working voltage produced low film contrast, high film definition, and low scatter. Low working voltage produced high film contrast, low film definition, and high scatter. Based on our results, a working voltage of 260 kV is most appropriate for effective analysis.

In selecting from a repertoire of traditional kinetics experiments, an instructor often has to choose among having students gain experience with the graphical method, the method of initial rates, o...

Object: The wide spread of gadgets among modern schoolchildren and their intensive use during breaks in school corridors and recreation areas indicates the necessity of improving illumination in school recreation areas to secure conditions suitable for intensive visual work. Thanks to their technical characteristics, durability and affordable price, LED light sources can ensure the implementation of this task. The objective of the study was to assess the impact of LED lighting of school corridors, halls and recreational facilities on visual acuity and psycho-emotional state of first graders in the course of a schoolyear. Materials and methods: In the corridors and recreation areas of the Dolgoprudninskaya Gymnasium (Moscow Region), fluorescent lamps were replaced by PrLUX-AU-36 LED lamps with Epistar LEDs, opal diffuser, 3600Lm luminous flux, and the color temperature of 4000K. Measurements of artificial lighting were taken before and after installing LED lamps using a TKA PKM 43 light meter. We conducted a study of visual acuity among 67 first graders (aged 7-8) in the annual dynamics from September to May using the Sivtsev-Golovin table placed in the Rota apparatus. Testing was conducted by a highly qualified ophthalmologist. The psycho-emotional state was assessed using the Luscher color test. Results: We observed a significant increase in visual acuity in children over the specified period indicating the absence of negative effects of LED lighting on the organ of vision. The results of the Lusher test proved the absence of negative dynamics, thus demonstrating null adverse health effects of LED lighting in the primary schoolchildren. The studies confirmed that the influence of that light load on vision and its negative non-visual effects were only potential.

Introduction: To uncover a relationship between light exposure and myopia is complicated because of the challenging nature of measuring visually relevant illumination experienced by children. Objective: To find a methodology to measure face illuminance using a mobile device. Methods: Accuracy and precision of the mobile device’s built-in ambient light sensor were tested under three different lighting conditions: full-field, a single small light, and one mimicking typical office illumination. Face illuminance was computed in six faces with different skin reflectances using pixel values in face images captured by the device camera placed at 30 cm in front of the face. The results were compared with those obtained with a commercial light meter situated at the face. Results: The illuminance measured by the device’s ambient light sensor showed high linearity (R2 &gt, 0.99) slightly under-estimating or conversely over-estimating face illuminance with full-field or single light sources but accurate for office lighting. Face illuminance measured by the devices’ camera under indoor conditions using the new methodology showed a mean relative error of 27% and a high linearity (R2 &gt, 0.94). Conclusions: Introduction of an app can be used to assess the association between visually relevant environmental light levels and myopia progression.

An experimental setup is presented which allows the study and characterization of integrated optical sensors. The system consists of a small integrating sphere that can be illuminated by various sources such as white and colored LEDs, calibrated sources, or halogen lamp types. The design allows easy installation and configuration of measuring instruments (light meter, standard calibrated photodiode). The control of the parameters of the tested sensors, data collection, and processing is performed using a microcontroller ESP 32 in the LabVIEW programming environment. Preliminary studies of the characteristics of color sensors and calibrated sources are presented.

Experiments with biological samples require precise control of environmental conditions. In our work we use zebrafish (Danio rerio) to understand the neurobiology of sleep, which requires precise control of temperature and lighting. Like many labs, lighting and temperature in the animal facility are centrally controlled in the building. During behavioral experiments and microscopy sessions, we use custom-built heating systems and perform occasional manual checks of conditions. However, without a system to precisely record conditions, gradual changes in temperature can go unnoticed for a long time, and temporary failures may be missed entirely. Here we present the design and characterization of affordable open-source tools to record temperature and light conditions during animal experiments using an Arduino microcontroller or a Raspberry Pi compact computer. The waterproof temperature sensor has high stability over 50 days of recording and is precise to 0.1°C. The Arduino device can be used through a common serial port interface for which we present code in Python and MATLAB. The Raspberry Pi version can be accessed through a web interface, for which we provide an installation guide. We use the device to record and review temperature and lighting conditions in two zebrafish animal facilities. We use our platform to add a water heating system to maintain temperature at 28°C during in vivo light-sheet imaging of larval zebrafish. We show that a change in temperature from 28°C to 32°C affects resting heart rate of the animal, highlighting the importance of maintaining and recording conditions. The protocols presented here do not require advanced engineering, fabrication, or software skills, and provide an approach to accurately record and report experimental conditions.

Background: Poor sleep is common among older adults at risk for dementia and may be due to circadian dysregulation. Light is the most important external stimulus to the circadian clock and bright light therapy (BLT) has been used for >20 years to help realign circadian rhythms. However, the ability of field methods (e.g., actigraphy) to accurately determine the type and intensity of light is unknown. Objective: We examined the ability of the MotionWatch8 (MW8) light sensor to determine: 1) light versus dark, 2) electrical light versus daylight, and 3) device-based BLT versus light which was not BLT. Methods: We tested the MW8 under 17 daily light scenarios. Light exposure data was collected for 5 minutes during each scenario. Concurrently, we measured light exposure using the LT40 Light Meter, a sensitive measure of light intensity. We then developed individual cut-points using receiver operator characteristics analyses to determine optimal MW8 cut-points for 1) light versus dark; 2) electrical light versus daylight; and 3) light from a BLT box versus light which was not BLT. Bland-Altman plots tested the precision of the MW8 compared to the LT40. Results: The MW8 accurately discriminated light versus dark (>32 lux), and electrical light versus daylight (

The smart cities programme is at the core of Saudi Arabia’s Vision 2030. The development of smart cities is based on adapting innovative technologies and solutions to meet local needs and possibilities in order to reduce both cost and energy resources consumption. In smart cities, more than 40% of electrical energy consumption should be saved. One of the most important electrical energy saving techniques is the application of the Solatube daylight system in sustainable buildings. In the present paper, an experimental investigation into the Solatube daylight system is performed according to the local climate conditions of Taif city, Saudi Arabia. A test chamber was designed with dimensions of 1 m3, made from medium density fibreboard. The model of Solatube used in the present research is Solatube 160 DS, 10” in diameter and with a length up to 30’. The HS1010-LCD digital light meter is used for measuring light intensity. A comparison of illumination obtained from the Solatube with that obtained from artificial bulbs of standard ratings was made at two different vertical distances inside the test chamber (z = 0.8 m, z = 1.0 m). The results showed that the Solatube, at both vertical distances, gave a better illuminance than standard artificial bulbs. Moreover, the results indicated that the Solatube daylight system converted about 60% of sunlight to passive light inside the test chamber. Generally, it is concluded that the Solatube daylight system can be efficiently used in residential, commercial, or industrial buildings in smart cities according to the available solar characteristics.

In photoplethysmography, light source and light detector are employed such that the received signal corresponds to a particular information needed. This research used five different LEDs as light sources. Phototransistor and LDR, on the other hand, were used as light detectors to assess the photosensitivity of human skin. Backscatter simulation was used to compare the photoplethysmographic detection of LDR and phototransistor. The aims of this study include: determine the optical response of a human skin, particularly the skin on the dorsal and palmar parts of the hand; conduct simultaneous simulation using modular and backscattered setup; provide measured value based on the conducted simulations. In every LED color and for both light detectors, ten test conditions were performed, namely: (1) room light on; (2) room light off; (3) room light on - black paper; (4) room light off - black paper; (5) room light on - white paper; (6) room light off – white paper; (7) room light on – dorsal skin; (8) room light off – dorsal skin; (9) room light on – palmar skin; and (10) room light off – palmar skin. Two different simulations were conducted involving all test conditions. The second simulation used light meter which showed similarity in behaviour of obtained values vis-à-vis barcode meter and ADC voltage. The modular involved a lux sensor which checked the findings on the reflectivity of skin Types III and IV of the Fitzpatrick scale and melanocytic naevi skin. The series of simulations conducted proved that the yellow LED provided highest sensor response and phototransistor greater sensitivity than LDR in detecting the received signals. Room light off condition was necessary to reduce the effects of ambient light. Keywords: Photoplethysmography, Backscatter simulation, Phototransistor, LDR, Optical response

Purpose: To evaluate light exposure from microscope versus intracameral illuminations to patient's and surgeon's retina during cataract surgery. Methods: Thirty consecutive patients who had cataract surgery using microscope and intracameral illuminations. At the point of the ocular of an operating microscope, optical illuminance and irradiance from the microscope illumination (60, 40, 20% intensity) and the intracameral illumination (60% intensity) were measured using a light meter and a spectrometer at a pause after lens capsule polishing in cataract surgery. Results: Average illuminance (lux) was 1.46, 0.66, 0.27, and 0.1 from 60%, 40%, 20% intensity microscope illuminations and 60% intracameral illumination. Average total spectral irradiance (μW/cm2) was 1.25, 0.65, 0.26, and 0.03 from 60%, 40%, 20% intensity microscope illuminations and 60% intracameral illumination. Conclusion: Microscope ocular illuminance and irradiance during cataract surgery were higher in the microscope illumination than in the intracameral illumination. It suggests that light exposure reaching patient's and surgeon's retina during cataract surgery is lower in the intracameral illumination than in the microscope illumination.

This study focused on the occupational risks experienced by healthcare workers in public hospitals. Studies have showed that factors in the physical environment such as noise, illumination, and temperature represent a significant risk among hospital staff. Ergonomic assessment was conducted to determine the risks associated with high noise level, low illumination level, and high indoor temperature. Survey questionnaires were distributed to 276 healthcare workers to obtain the RPN (risk priority number) in the selected areas in three public hospitals in Metro Manila, Philippines. Subsequently, noise, illumination, and temperature of these hospitals were measured using sound level meter, light meter, and digital LCD electronic thermometer respectively. The RPN and physical environment measurements were statistically analyzed to determine the areas with high occupational risk. Results of the study show that noise level and temperature have strong positive relationship with the occupational risks. As the measurements of these physical environment increases, the occupational risk experienced by the healthcare workers also increases. However, illumination level and the occupational risk have a moderate to strong negative relationship with each other. It can be implied that a dimmer surrounding causes problems to healthcare workers. It was also observed that the OPD, OB ward, ER, OB nurse station, pediatrics ward, and medicine ward have high occupational risk in terms of noise level. Meanwhile for illumination, areas with high occupational risks due to poor lighting are ER, OR, laboratory, pharmacy, OPD, OB nurse station, and surgical nurse station. For this reason, the researchers were able to design an ideal physical environment for the public hospitals using the principles of ergonomics.

Modern lightmeters are analyzed and the results of the development of a luxmetre with a dynamic range of ten orders and the methods of studying its metrological characteristics are presented, according to which the nonlinearity of the energy characteristic of the sensitivity of the luxmetre does not exceed ± 0,7 % in the range of illumination (1 · 10-5 – 1 · 105) lux, and the limits of the permissible basic relative error of measuring the illumination do not exceed ± 5 %.

Measurement of photosynthetically active radiation (PAR) incident on photosynthetic organisms is a crucial measurement for understanding how organisms respond to various light conditions, and for calculating electron flow through the photosynthetic machinery. Measurements of PAR are typically performed in the region of the electromagnetic spectrum between 400 - 700 nm, which is the region of radiation that is responsible for promoting photosynthesis. Typically, to ensure that the sensor measures in this range, the implementation of long- and short-pass filters is required. Although this allows the exclusion of radiation outside of the PAR region, such filters can be expensive. Additionally, the implementation of autonomous PAR measurements requires costly commercial instruments. Here, a straight-forward, inexpensive apparatus has been designed and constructed using a sensor that can distinguish between red, green, blue and white light. The constructed apparatus was able to perform comparably to a commercial PAR sensor. Furthermore, the implementation of the device to measure PAR intensity over a three-day period shows how the apparatus can be implemented for use as a constant light monitor.

Light is a propagation of electromagnetic waves that spread all directions that play an important role in everyday life because it is an absolute part of life and without the light of life on earth can not develop. The amount of light illuminance is necessary to know because basically humans require adequate lighting. The instrument for measuring light illuminance is a luxmeter or light meter. However, this gauge is difficult to obtain and the price of the tool is expensive so that it can only be found in certain school laboratories or colleges. While telemetry is the process of measuring the parameters of an object (objects, space, natural conditions) that the measurement results are transmitted to other places via data transmission without or using a cable (wireless). The purpose of this study is to measure, to know the conditions of light intensity. This research uses experimental model of light intensity measurement using independent measuring instrument with combination of LDR and Arduino uno consisting of transmitter and receiver. In the transmitter there are LDR, Arduino Uno, and RF Module Board 433 MHz components, while the receiver consists of Arduino Uno, laptop, and RF Module Board 433 MHz. In this design is also done a variety of testing tools using distance variables. Overall this tool is working well. The system has successfully delivered telemetry measurement results with a range of conditions without a wall barrier with a maximum distance of

Proposed and demonstrated for the first time is robust testing of optical displays using the extreme linear Dynamic Range (DR) CAOS camera. Experiments highlight accurate and repeatable CAOS camera-based testing of standard 8-bit (i.e., 48 dB DR) and modified DR 10-bit (i.e., 60 dB DR) computer Liquid Crystal Displays (LCDs). Results are compared with CMOS camera and light meter-based LCD testing highlighting the robustness of the CAOS camera readings.

Several measures, such as reduced lighting, may be adopted to minimise energy consumption while providing an optimal and safe level of road lighting. One approach to evaluate the safety impact of reduced road lighting is by using Geographical Information System (GIS) to identify road sections with low level of illumination and high risk of road traffic accidents. The GIS approach required a cost-effective and efficient system to measure the level of lighting provision at close intervals along a road network. This paper presents the development and validation of a road illumination measurement system developed for this purpose. The system is based on TSL2561 illumination sensors, u-blox NEO-6M GPS module, Robotdyn Arduino Mega Pro Embed and Catalex microSD shield. The results showed that the measurements obtained from the developed system followed a similar trend as a commercial light meter, and that it could be used to identify road sections with relatively low levels of illumination for further safety analysis using GIS.

Objective This study aimed to measure the light levels neonates would be exposed to during retrieval, determine whether this varied with transport mode, and compare them with recommended light exposure in neonatal intensive care units. We also aimed to determine the ease of use and acceptability of using the smartphone application. Setting A neonatal retrieval service in Brisbane, Australia. Methods This prospective study used the calibrated smartphone application Physics Toolbox Sensor Suite (Vieyra Software, Washington, DC). Data were collected during the outbound, nonpatient leg of 45 retrievals (25 road, 11 fixed wing aircraft, and 9 rotary aircraft journeys). Data were saved to Cloud storage and then analyzed using the PostgreSQL database. Results The median illuminance was 6 lux (interquartile range [IQR], 1-58). The maximum recorded was 93,842 lux. The median illuminance during daytime journeys was 15 lux (IQR, 2-77). The median light level for night journeys was 1 lux (IQR, 0.5-8). Illuminance exceeded the recommended level (600 lux) for 2.1% of all journey time. Conclusion Retrieved neonates can be exposed to light in excess of recommended neonatal intensive care unit levels, including extremely bright light. It is feasible, with good staff acceptability, for a calibrated smartphone application to be used in place of a light meter.

Accuracy in calculating exposure in photographic techniques is the key to being able to produce good quality photos. The light calculation includes three elements (Triangel Exposure), namely shutter speed (shutter speed / t), ISO sensitivity, and diaphragm (aperture / f). A light meter is a tool for calculating lighting in the world of photography to accurately calculate the light falling in or around the object to be photographed. The light meter has a working principle like a lux meter calculates the value of light intensity in a place. However, on a light meter for photography, there is a calculation of a triangle exposure in it. This light meter prototype uses an ATMega328 microcontroller on the Arduino Nano V3 with the help of a TSL2561 light sensor and a TCS34725 RGB color sensor. Tests were carried out by comparing the output value using an original light meter, namely Sekonik Flashmate L-308X with the continuous light shooting method. The results of the test using the original tool with the ATMega328 microcontroller produced values above 90%.

Purpose: The purpose of this study is to investigate changes of positive vergence and accommodative power with illumination. Methods: 49 subjects(mean age:24.51±2.82) having no systemic and ocular disease were recruited. Illuminance environment is going to use the light meter ((LX-101, Lutron, USA) and dimmers to change the light intensity from 10 lux to 1000 lux measured the amplitude of accommodation and far/near positive vergence. Results: Amplitude of accommodation was lowest to 8.51 D with 10 lux and the highest to 9.12 D with 800 lux. As the illuminance increases, the exponential decay fit(y=9.09-0.62e-) was maintained while also increasing amplitude of accommodation. Break point of distance positive vergence was higher by 20.81 △ at low illuminance of 10 lux, near positive vergence was higher by 21.42 △ at low illuminance of 10 lux. The exponential decay fit of Distance/near positive vergence were y=17.08+4.66e- and y=20.93+0.63e- , respectively. Conclusions: As the illuminance increases while amplitude of accommodation is increasing, Distance/near positive vergence was increase in low light, while temporarily reduced while increasing illuminance showed a pattern that changes less.

Nighttime visibility is an important consideration in collision reconstruction and personal injury investigation. Decreased contrast in low ambient lighting conditions can greatly affect human perception and response. Because ambient lighting levels change rapidly at dawn and dusk, forensic investigators must have an accurate knowledge of the time of day and the cloud conditions at the time of the incident before initiating a nighttime visibility assessment. Previously, human factors experts attempting re-enactments at dawn or dusk have had to wait for sky conditions that match those at the time of the incident, making the investigation of those cases extremely difficult, if not unfeasible. In this study, an ambient illumination equivalency tool has been developed based on a database of time-lapse light meter readings collected by the authors. This new tool can be used to facilitate nighttime visibility assessments on any day by providing a time adjustment factor to account for the changes in ambient illuminance due to differences in the cloud conditions between the day of the incident and the day of the re-enactment.

To test the effect of ambient illumination scaling on the reproducibility and reliability anterior chamber metrics using the Visante time domain optical coherence tomography (TD-OCT) instrument.The inferior irido-corneal angles of 25 normal, healthy eyes were imaged twice with the Zeiss Visante TD-OCT under five strictly controlled ambient light conditions (foot candles (fc) measured with a light meter at camera/eye interface). Each eye was imaged 10 times totaling 250 assessments. Angle opening distance (AOD500/750), trabecular iris space area (TISA500/750), and scleral spur (SS) angle were graded twice by masked, trained graders at the Doheny Imaging Reading Center using the Visante's intrinsic tools. Lighting effects on measurements, intra-/inter-grader and acquisition analyses, and Bland-Altman plots were computed using Statistical Package for Social Science (SPSS Inc. version 18.0, Armonk, NY).With a near linear relationship of angle metrics to lights levels (RThe results of this study show the high sensitivity of the anterior chamber to changes in the illumination. The slight decrease in light had a corresponding large decrease in Anterior Chamber Angle (ACA) metrics. With clinical diagnoses and treatments of eye diseases relying on these angle measurements, these findings emphasize the importance of strictly controlling light conditions in order to obtain reproducible measurements of anterior chamber geometry.

The study intends to improve walkability in the walkways by providing better illuminance levels. Firstly, the study has defined the existing typology of walkways in the campus then selected the worse type-with less protection from the sun-for further improvement. The methodological tools used in the study were: a field survey, illuminance meter, and an Integrated Environmental Solution Virtual Environment (IESVE) software packages. The questionnaire was used to understand the right feedback on the existing walkways. The lowest ranked satisfactions received from the respondents were from excessive brightness and temperature in the walkways. Thus, this paper proposes a successful envelope layout solution that provides better lighting levels and glare-free spaces. The Islamic style pattern used in the campus design was considered for the proposed simulations. Light meter was used to measure the existing illuminance levels in the corridors. Accordingly, four cases with several parameters such as the integration of shading elements: fully or partially, and vertically or horizontally in addition to the flooring materials were conducted in the simulation. Lastly, the study could provide a design layout as a proposal that provides glare-free walkways.

Resumo Este trabalho apresenta o projeto de um medidor de luz para atividades didáticas experimentais utilizando o sensor de luz integrado BH1750. O medidor de luz é construído conectando o sensor BH1750 com a plataforma Arduino. Os dados são transferidos para um computador e são visualizados durante a execução de um experimento por meio de tabelas e gráficos em tempo real. São apresentadas as características físicas e operacionais do sensor BH1750, bem como o projeto eletrônico e a programação computacional. Os resultados de desempenho do medidor de luz proposto neste trabalho em comparação a um de referência indicam que não há diferença estatisticamente significante entre eles em relação às medidas de iluminância. Para ilustrar alguns usos didáticos do medidor de luz desenvolvido neste trabalho, é apresentada uma investigação da dependência da atenuação de luz com a distância, assim como um fotômetro de LED para estudos em espectroscopia de absorção molecular e uma investigação da variação de iluminância da lâmpada fluorescente. Ressalta-se, ainda, o potencial de uso de um medidor de luz como o apresentado aqui nas práticas de ensino de ciências que buscam a inovação e o engajamento dos alunos em projetos interdisciplinares. Abstract This work presents the design of a light meter for experimental didactic activities using the integrated light sensor BH1750. The light meter is built by connecting the BH1750 sensor with the Arduino platform. The data are transferred to a computer and they are viewed during the execution of an experiment by means of tables and graphs in real time. The physical and operational characteristics of the BH1750 sensor are presented, as well as the electronic design and computational programming. Results of performance of the light meter proposed in this work compared to a reference one indicates there is no statistically significant difference between them concerning the illuminance measurements. For illustrating didactic some uses of the light meter developed in this work, an investigation of the dependence of light attenuation with distance is presented, as well as a LED photometer for studies in molecular absorption spectroscopy and an investigation of the fluorescent lamp illuminance variation. It is also emphasized the potential use of a light meter like that presented here in science teaching practices seeking innovation and the engagement of students in interdisciplinary projects.

Spectral bandwidth (SB) of ultrashort laser pulses (under 100 fs) in commonly used near-IR range can be tens of nanometers. When selecting laser eyewear for use with ultrashort pulses, the “effective” optical density (ODeff) should be calculated from a convolution of the spectral curve for the filter transmission with the spectrum of the laser pulse. We present model calculations of ODeff curves (ODeff versus wavelength) for selected commercial eyewear filters at different pulse durations, assuming a gaussian laser spectrum.Visible light transmission (VLT) is another important laser eyewear characteristic. We use the definition for photopic luminous transmission in the Z136.7-2008 standard to calculate VLT values by convoluting the manufacturer transmission curves with the photopic luminous efficiency function and the spectrum for a CIE Standard Illuminant C source that approximates average daylight over the visible range. We then compare the calculated VLT with what the manufacturers provide and with “lab VLT” measurements that we have made using a light meter and a source provided by standard lab fluorescent or LED lighting.Spectral bandwidth (SB) of ultrashort laser pulses (under 100 fs) in commonly used near-IR range can be tens of nanometers. When selecting laser eyewear for use with ultrashort pulses, the “effective” optical density (ODeff) should be calculated from a convolution of the spectral curve for the filter transmission with the spectrum of the laser pulse. We present model calculations of ODeff curves (ODeff versus wavelength) for selected commercial eyewear filters at different pulse durations, assuming a gaussian laser spectrum.Visible light transmission (VLT) is another important laser eyewear characteristic. We use the definition for photopic luminous transmission in the Z136.7-2008 standard to calculate VLT values by convoluting the manufacturer transmission curves with the photopic luminous efficiency function and the spectrum for a CIE Standard Illuminant C source that approximates average daylight over the visible range. We then compare the calculated VLT with what the manufacturers provide and with “la...

This paper describes our approach to remove the effect of the Pupillary Light Reflex (PLR) component from pupil diameter signals obtained by an Eye-Gaze Tracking device (Eyetech Digital TM3) using the RGB camera from Kinect as a way to measure the illuminance around the eyes of the user. The purpose of this study is to obtain filtered pupil diameter signals that mainly contain the Pupillary Affective Response (PAR) used to estimate the arousal level in the response of a human subject to affective stimuli. The approach includes using the Adaptive Interference Canceller (AIC) technique to filter out the Pupillary Light Reflex (PLR) from pupil diameter signals (PD). We also present the empirical method followed to replace a stand-alone light meter with the RGB camera from Kinect to measure illuminance.

Целью данной работы является проектирование системы контроля освещением. Нужно сделать список Ñ‚ÐµÑ Ð½Ð¸Ñ‡ÐµÑÐºÐ¸Ñ Ñ‚Ñ€ÐµÐ±Ð¾Ð²Ð°Ð½Ð¸Ð¹ к системе, список ее Ñ„ÑƒÐ½ÐºÑ†Ð¸Ð¾Ð½Ð°Ð»ÑŒÐ½Ñ‹Ñ Ð²Ð¾Ð·Ð¼Ð¾Ð¶Ð½Ð¾ÑÑ‚ÐµÐ¹ и описание. Для разработки требований к системе нужно провести анализ ÑÑƒÑ‰ÐµÑÑ‚Ð²ÑƒÑŽÑ‰Ð¸Ñ ÑÐ¸ÑÑ‚ÐµÐ¼ контроля освещением. Разработаны: ÑÑ ÐµÐ¼Ð° подключения датчиков; алгоритмы функционирования системы, представленные в виде блок-ÑÑ ÐµÐ¼Ñ‹ алгоритма программы для МК., The purpose of this work is to design a lighting control system. It is necessary to make a list of system technical requirements, a list of its functional capabilities and a description. To develop system requirements, it is necessary to analyze existing lighting control systems. Developed: sensor wiring diagram; algorithms of system functioning, presented in video block schemes.

This study aimed to design a Greenhouse Remote Monitoring system and to immediately evaluate the monitoring system. The Monitoring system was designed based on the NodeMCU ESP8266 microcontroller to expectedly result an Android monitoring display as the output. This research was conducted in Greenhouse at Faculty of Food and Agroindustrial Technology, University of Mataram. An experimental method using greenhouse and hydroponic system was applied to this research. The monitoring system consisted of components that functionally related to each other (NodeMCU ESP8266, Android, DHT11 (temperature and humidity sensor), BH1750 (light sensor), Total Dissolved Solid (TDS) sensors, and other components that further supported by programming language. The observed parameters were the greenhouse temperature (°C); humidity (%); light intensity (lux); and the amount of TDS (ppm). The experiment indicated that the designed monitoring system successfully displayed what the sensor had read then translated it into Android. The average percentage of the Light meter reading errors using the BH1750 sensor (shown) on Android was 2.13%; the average percentage of the hygrometer reading errors using DHT11 sensor on Android was 0.14%; the average value of the thermometer reading errors as well as DHT11 sensor on Android was 0.76%; while the average TDS reading error on Android was slightly above 5% due to increasing temperature inside the greenhouse, especially in the afternoon period.

This paper presents a comparison of energy consumption and average lighting level between two different lighting systems of an Academic Building, firstly, the existing lighting system using T8 tube fluorescent lamps, and secondly, a proposed lighting system with T8 tube LED lamps. The main objective of this comparison is to find the power consumption and lighting level difference between fluorescent and LED tube lamps used in the same space, as in this case, a classroom. A second objective is to measure the lighting level inside the classroom to make sure that the existing lighting standard in Mexico is been satisfied. The measurements were performed using a power analyzer and a light meter to evaluate the actual power consumption and lighting levels using T8 tube fluorescent lamps, and the proposed retrofitted T8 tube LED lamp system. Lighting is the most important load in offices and classrooms buildings, for that reason, this kind of load has been studied by a lot of researchers. This comparison will provide information about the energy consumption and lighting level of a classroom, helping to know if the classroom accomplishes with the legal Mexican lighting standard. Additionally, will generate information about the energy savings obtained by the LED lighting system over the existing fluorescent lighting system.

Diplomsko delo prikazuje izdelavo tehnične dokumentacije merilnika svetlobe, katera bo uporabljena za serijsko proizvodnjo pri zunanjih proizvajalcih. Z merilnikom, ki se povezuje z zunanjimi napravami, merimo jakost ambientalne svetlobe, bliske svetlobe in barvno temperaturo. V uvodnem delu so predstavljeni sestavni kosi in kratko delovanje naprave. V osrednjem delu so prikazani postopki izdelave tehnične dokumentacije na podlagi mednarodnih standardov tehnične dokumentacije in pravil tehničnega risanja. Diplomsko delo se osredotoča na predpisovanje dimenzijskih in geometrijskih toleranc sestavnih kosov, ki so ključni za sestavljivost sestavnih kosov, natančne meritve parametrov svetlobe in videz tehnološke dovršenosti merilnika svetlobe. V zaključnem delu so predstavljene najpomembnejše ugotovitve in predlogi za nadaljnje delo. The thesis presents the production of the technical documentation of a light meter, which will be used for serial production by outsourced manufacturers. The light meter, which connects to external devices, measures the intensity of ambient light, flash strobes light and color temperature. The introductory part presents the components and the short working principles. The central part shows the procedures for the production of technical documentation based on international standards of technical documentation and technical drawing rules. The thesis focuses on prescribing dimensional and geometric tolerances of assembly pieces, which are crucial for the assembly of the components, precise measurements of the light parameters and the appearance of the technological perfection. In the conclusion of the thesis, the most important findings and proposals for further work are presented.