Vernier Software and Technology
Vernier Software & Technology
Tech Info Library

Potassium Ion-Selective Electrode Troubleshooting and FAQs

Potassium Ion-Selective Electrode, order code K-BTA, $199
Specifications and User Guide

TROUBLESHOOTING
-Primary Test: Check the raw voltages while calibrating in the standards. The high (1000 mg/L) should be around 2.7 volts. The low (10 mg/L) should be around 1.9 volts.
-Secondary Test: Refer to TIL 665: General tips for using Ion Selective Electrodes (ISE).

RELATED TIL ENTRIES
-TIL 1060: Do any of your sensors require special storage?
-TIL 759: Do you sell ISE Standards?
-TIL 1296: How can I have my ISE read mV output instead of mg/L?
-TIL 3389: How do I sterilize an Ion-Selective Electrode?

SPECIFICATIONS
-Range: 90 to 39,000 mg/L or ppm
-Interfering ions: Cs+, NH4+, H+, Ag+, Na+, Li+
-Approximate calibration voltages: High (100 mg/L) 2.7 V, Low (1 mg/L) 1.9 V
-Reproducibility (precision): ± 11% of full scale
-Accuracy: ±16 % of full scale
-Temperature range (can be placed in): 0 to 40°C (no temperature compensation)
-Electrode slope: +56 ± 3 mV/decade at 25 degC
-pH range: 2 to 12 (no pH compensation)
Minimum immersion: 1.1 inch
Electrode length: 155 mm
Body diameter: 12 mm
Cap diameter: 16 mm
Cable length: 100 cm

CALIBRATION
-Calibrate? Yes. Conduct a two-point calibration, using the standard solutions that are shipped with the sensor. First point: The ISE should be soaking in the High Standard. Enter the concentration value of the High Standard. Second point: Remove the ISE from the High Standard, rinse well with distilled water from a wash bottle, and gently blot dry with a paper towel or lab wipe. Place the electrode into the Low Standard. Wait until the voltage value stabilizes; this may take several minutes. Enter the concentration value of the Low Standard.
-Important: Make sure the ISE is not resting on the bottom of the container and that the small white reference contacts are immersed. Make sure no air bubbles are trapped below the ISE. Hold the ISE still and wait for the voltage reading to stabilize.

RELATED VERNIER PRODUCTS
-Potassium ISE Replacement Module, Potassium Replacement Module, order code K-MOD, $79
-Potassium ISE Low Standard, Low Standard Potassium Solution, order code K-LST, $18
-Potassium ISE High Standard, High Standard Potassium Solution, order code K-HST, $18

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