Answer:
The lack of accuracy and underestimation of absorbance readings obtained from the colorimeter can be contributed to many experimental factors. One plausible error is from the imperfection of the absorber, in that it may not completely absorb the stray light passing by the perimeters of the photoresistor.
Explanation:
In practice there are other sources of error, such as environmental effects on photometer and sample, temperature, line voltage fluctuations, vibrations, contamination, or heating of the sample by the photometer. All these factors may impair the measured result, and ways and means are known to test and eliminate them.