Measuring Light Intensity

Abstract To investigate whether the inverse relationship between light intensity and distance squared is related to the actual situation and credibility under laboratory conditions. In addition, the techniques used in the experiment included measuring the distance from the light source to the light sensor, recording the light intensity of the light source, and accurately recording the observation result. Light from the light source through the paperboard bobbin changes as the distance from the light sensor increases.

A spectrophotometer is a device for measuring the light intensity used to determine the protein content of each mixture and functions by measuring light intensity as a function of color or more specific wavelength light (Global Water Instrumentation Inc, 2007). (Appendix 2) Thus, the lower the reading, the less light is absorbed by the solution being tested, in this case the enzyme (pepsin) digests more protein (egg protein), the lower the reading, the more enzyme It indicates that the reaction rate is fast.

Spectrophotometry involves the use of a spectrophotometer. A spectrophotometer is a photometer (a device for measuring light intensity) which can measure intensity as a function of color (more specifically, wavelength) of light. An important feature of spectrophotometers is the linear range of spectral bandwidth and absorption measurements. There are two types of equipment, single beam and double beam. The dual beam spectrophotometer compares the light intensities between two light paths, one path containing the reference sample and the other path containing the test sample. The single beam spectrophotometer measures the relative light intensity of the beam before and after the insertion of the test sample. Although comparative measurements of two beam measuring instruments are simpler and more stable, single beam instruments can have a wider dynamic range and the optics are simpler and more compact.

Laboratory spectrophotometers are generally divided into single beam and dual beam spectrophotometers. The single beam apparatus measures the difference in light intensity between the reference sample and the test sample. In the dual beam model, the light source's light source is split into two parts. One illuminates the sample and the other illuminates the sample. Thus one beam has a reference sample of known characteristics and the other beam contains a test sample. Absorbance is measured as the difference between transmitted light intensity and non-transmitted intensity. The spectrophotometer model used depends on the type of test that must be performed