This document describes the calibration procedure for the CHY Light Meter, including offset calibration and calibration under four standard illuminant sources.
The document outlines the offset calibration process, which involves turning off power, covering the sensor head, connecting a battery, and shorting specific pins before powering on to display 'CAL'.
Following the offset adjustment, the guide details how to calibrate the meter under four standard illuminant sources (A, B, C, and D) with values near 18.5, 185, 1850, and 18.5k Lux.
The standards used are CHY 18.86, 182.3, 1820, and 181.2k Lux respectively.
The LCD display should show 'A' once the meter is left on steadily.