Measuring Hints - Hach Pocket Colorimeter II Instruction Manuals

pH
(6.0 to 8.5 pH units)
For water and wastewater
Phenol Red Method

Measuring Hints

• For greatest accuracy, use the Standard Calibration Adjust to adjust the
calibration curve with each new lot of Phenol Red. Use the pH 7.00 Buffer
Solution included in the kit.
• Periodically, recheck with the pH 7 Buffer to confirm the accuracy of the
instrument and method. If not reading within 0.1 pH unit, recalibrate the
instrument.
• The amount of indicator and sample is critical for accurate results and should
be measured carefully.
• Attempting to measure a sample with a pH below 6.0 or above 8.2 will result
in an inaccurate reading. Measurements outside the range can differ from the
true pH reading by as much as 2 pH units.
Note:
The Pocket Colorimeter II is designed to measure solutions contained in sample cells.
dip the meter in the sample or pour the sample directly into the cell holder.
DO NOT
1—69
Method 10076