1—69
pH (6.0 to 8.5 pH units)
For water and wastewater
Method 10076
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.
DO NOT
dip the meter in the sample or pour the sample directly into the cell holder.