The Q-Certification verifies the calibration / photometric accuracy of the Chematest under test by comparison with a reference instrument. The comparison is performed for DPD-based chlorine determinations (APHA 4500-Cl G (2017) and DIN EN ISO 7393-2) at four different chlorine concentrations between 0.1 ppm and 4.5 ppm which are simulated by liquid absorbance standards.
The calibration of the reference Chematest is periodically verified with NIST-traceable potassium permanganate standards according to APHA 4500-Cl G (2017) and DIN EN ISO 7393-2.