Calibration Standard HI 706 Checker HC ®

Range 0.0 - 99.9 ppm NH3-N | Nessler Method | 0.1ppm resolution

Range 0:00 to 2:50 ppm | USEPA Method 330.5 / DPD | Resolution 0.01ppm

Range 0:00 to 3:00 ppm NH3-N | Nessler Method | 0.01ppm resolution

The HI 761 uses an adaptation of the USEPA method 330.5. The reaction between the chlorine and DPD reagent causes a pink tint in the sample.