Profile: Advance Testing Instruments And Services specializes in providing laboratory testing equipments. Colorimeter is a three-filtered instrument that are known to use three different color filters such as, red, green, and blue that imitates the human eye response to color and light. Portable spectrophotometers are the prefect instruments to test physical samples using full spectrum color measurement. These devices analyse the spectrum of a sample?s reflectance by each wavelength as well as other properties that includes the absorbance or transmittance.