+ pH: – 2.00 to 16.00 pH
+ mV: ± 699.9 mV; ± 2000 mV
+ Temperature: – 20.0 to 120.0 °C
+ pH: 0.01 pH
+ mV: 0.1 mV (± 699.9 mV); 1 mV (± 2000 mV)
+ Temperature: 0.1 °C
+ pH: ± 0.01 pH
+ mV: ± 0.2 mV (± 699.9 mV); ± 1 mV (± 2000 mV)
+ Temperature: ± 0.2 °C (excluding probe error)
pH Calibration: Up to 5 point calibration, 7 standard buffers available (1.68, 4.01, 6.86, 7.01, 9.18, 10.01, 12.45)
Temperature Compensation: Manual or automatic from -20 to 120°C
Temperature Probe: HI 1131P glass body, single junction, refillable with BNC connection and 1 m Cable HI 7662 stainless steel probe
PC Connection: USB
Data Logging: 100 points
Dimensions: 235 x 222 x 109 mm (9.2 x 8.7 x 4.3")
Weight: 1.3 kg (2.9 lb.)
- pH Calibration Check™
- On-screen electrode condition and response time
- Up to five point calibration with seven standard buffers
- Diagnostic alerts through icons
- Automatic Temperature Compensation
- GLP features
- PC interface via USB
A properly manufactured and maintained pH electrode will retain its measuring integrity for a long time. As a result of many factors such as age, poor maintenance or improper handling, any electrode in time will lose its integrity.
The most common cause for pH measurement inaccuracies is an unclean or improperly cleaned electrode. This is very important to note, because during calibration, the instrument assumes that the electrode is clean and that the standardization curve created during the calibration process will remain a valid reference until the next calibration.
A dirty electrode or wrong calibration approach can contribute to buffer solution contamination. A contaminated buffer solution can present a major problem during calibration due to the fact that it is considered the only reference.
The HI 2221 is a pH benchtop meter featuring our exclusive Calibration Check™ diagnostics for both pH?electrodes and buffer solutions during calibration. This instrument compares the characteristics of the pH electrode from one calibration to the next. In the case of large variances in the electrode condition, it alerts the user that the electrode needs to be properly cleaned prior to calibration and measuring.
The second feature is to detect if the calibration buffer solution is contaminated. After calibration, the probe condition is evaluated and an indicator is displayed informing the user of the overall pH electrode status.
This instrument can measure using ORP electrodes (pH channel input), due to it’s capability to measure mV with a resolution up to 0.1 mV.
This meter also features five point calibration with seven standard buffers, Automatic Temperature Compensation and GLP capabilities that allow for the storage and retrieval of all data regarding pH. With a built-in logging function, measurements are stored in non volatile memory and can be transferred to a PC through the USB port.