An experiment was performed where a quartz-iodine lamp was used to measure the photocurrent in microamperes in intervals of 10 nm from 400 nm to 900 nm for the voltage settings of 60, 80, 100, and 120V.
Some of the consistent irregularities in the photocurrent data could have been eliminated by using a different lamp, but experimenter chose not to. What experimental reason could there be for this decision?