Calibration

For proper quality control, all Oakton PCS 35 TESTRs need to be calibrated with in 24 hours prior to sampling.  We recommend that you calibrate the sensor at home before you leave to monitor.  All calibrations should be done with new solutions that have not expired.

Here are instructions for how to calibrate the Multi-parameter TESTR 35 for Conductivity and pH

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Steps for Conductivity Calibration

Illustration

Remove sensor cap and rinse the sensor under warm tap water for one minute

or

After extended period without use (2 months or more), remove the sensor cap and soak the sensor in warm tap water or pH 4 buffer for approximately 1 hour and then rinse with tap water.

Press "ON/OFF" to turn on meter and select "MODE ENT" until "Cond Auto" comes up on the screen

          

Immerse the sensor in the 1413 conductivity standard and push "CAL".

The larger number on top is the uncalibrated value, while the smaller bottom number should change and lock on the closest automatic calibration value.

Wait until the reading settles (1-2 minutes) and record the top number under "Initial Meter Reading" on the data sheet.


Press "MODE ENT" to confirm the calibration value.

The top number will flash after it has been calibrated.  Record this new number under "Post Calibration Reading".

For quality control purposes Post Calibration Readings need to be with-in the range of 1343 - 1483 µs/cm.  If the post calibration reading is not in this range please try to recalibrate again.  If there are still problems, contact your local watershed coordinator or the UWW program coordinator.

For full instructions on how to use the Multi-parameter TESTR 35 click here.


Steps for pH Calibration (3 point calibration)

Illustration

Remove sensor cap and rinse the sensor under warm tap water for one minute.

or

After extended period without use (2 months or more), remove the sensor cap and soak the sensor in warm tap water or pH 4 buffer for approximately 1 hour and then rinse with tap water.

Press "ON/OFF" to turn on meter and select "MODE ENT" until "pH" comes up on the screen

    

Immerse the sensor in the pH buffer and push "CAL".

The larger number on top is the uncalibrated value, while the smaller bottom number should change and lock on the closest automatic calibration value.

Allow time for the top number to stabilize (1-2 min), then record the top number under "Initial Meter Reading" on the data sheet.

Next press "MODE ENT" to confirm the calibration value. The initial number will briefly blink before the post calibration number displays.

Record this new number under "Post Calibration Reading".

Repeat steps 3 and 4 for additional buffers (4.01, 7.00, and 10.01).

For quality control purposes Post Calibration Readings need to be no more than +/- 0.1 of the calibration standard (ie, for pH 7 standard, 6.9 to 7.1).  If the post calibration reading is not in this range please try to recalibrate again.  If there are still problems, contact your local watershed coordinator or the UWW program coordinator.

For full instructions on how to use the Multi-parameter TESTR 35 click here.