Measuring light with light-dependent resistors: an easy approach for optics experiments

Abstract

We entertain the use of light dependent resistors as a viable option as measuring sensors in optics laboratory experiments or classroom demonstrations. The main advantages of theses devices are essentially very low cost, easy handling and commercial availability which can make them interesting for instructors with limited resources. Simple calibration procedures were developed indicating a precision of ∼ 5% for illuminance measurements. Optical experiments were carried out as proof of feasibility for measurements of reflected and transmitted light and its quality results are presented. In particular, the sensor measurements allowed to verify the angular distribution of a Lambertian reflective material, to observe transmitted and reflected specular light on a glass slab as function of the incoming angle of a light beam, and to estimate glass refractive index with values averaging 1.51 ± 0.06 in satisfactory agreement with the expected 1.52 value.

Fabrication and Characterization of a Highly Sensitive and Flexible Tactile Sensor Based on Indium Zinc Oxide (IZO) with Imprecise Data Analysis

“…From the above-given Figures and , it is clearly seen that we have used error graphs in the classical approach (as general research has used such graphs to express the variation of data in the work − ) for capacitance and resistance values. However, it is not much flexible and informative because the graphs only show the uncertainty of data.…”

Modeling of A LDR Based Liquid Level Detecting Device Using Power Function

“…It can be established from Equation ( 2) that = ( ); and, must therefore be linked to . One of the ways of achieving this is by invoking Inverse Square Law (ISL), which states that the luminance is proportional to the inverse square of the source-sensor distance [12]; that is…”

“…Determination of values of , : According to [12] the values of , , in Equations ( 10) and ( 11) are function of the colour of light received by the LDR used. In this paper, red LED was used as the light source, because red beam of light can be dispersed easily when reflected from the surface of the liquid [12]. The values of , , based on red colour received by LDR are × , , 0.68 [11] respectively.…”

“…The values of , , based on red colour received by LDR are × , , 0.68 [11] respectively. Figure 6 Experimental setup of measuring light with LDR [12] Figure 7 The plot of ( )against ( ) Determination the values of and : For the purpose of computing the values of in Equations ( 10) and (11), the experimental procedure in measuring light with LDR proposed by [12] was adopted and implemented.…”

A simple calibration experiment for light dependent resistors using Malus law

“…They have observed that the LDR is more sensitive in low light levels and can be utilized for imaging in a dark setup. Other methods to calibrate the LDR include decreasing the source-to-sensor distance [15], or putting filters with known transmittance functions such as microscope slides to reduce the incident light intensity [16].…”