LaMotte Tracer pH Meter - Manual (Page 9)

9
Preparation of Buffers
1. Fill a sample cup with 20 mL of distilled or deionized water.
2. Add one buffer tablet:
pH 4.0 Code 3983A
pH 7.0 Code 3984A
pH 10.0 Code 3985A
3. Use the tablet crusher (0175) to crush the tablet. Stir until the tablet has
disintegrated.
NOTE: Buffers should be prepared fresh daily.
pH Calibration
The TRACER can be calibrated at 1, 2 or 3 points. For the most accurate
results with a two point calibration, calibrate the TRACER with a pH 7 buffer
fi rst, then calibrate with either a pH 4 or pH 10 buffer whichever is closest
to the pH value of the sample to be tested. When performing a three point
calibration, calibrate with the pH 7 buffer fi rst, followed with the pH 4 buffer
and then the pH 10 buffer.
1. Place the electrode into a buffer solution (4, 7, or 10 pH) and press the
CAL/RECALL button. Typically, pH 7 is calibrated fi rst, then 4 or 10,
depending on the measurement range. If readings are going to be made
over the entire range, calibrate with 4, 7 and 10 buffers.
2. The TRACER will automatically recognize the solution and calibrate
itself to that value. The circled number on the display will match the pH
of the buffer. Note that if the buffer is more than 1 pH unit off from the
4, 7, or 10 pH buffer, the TRACER will assume an error and abort the
calibration.
CAL
and
END
will be displayed.
3. During calibration, the pH reading will fl ash on the main display.
4. When calibration is complete, the TRACER will automatically display
END
and return to the pH measurement mode.
5. Rinse the electrode with distilled water.
6. The appropriate circled indicator (4, 7, or 10) will appear on the display
when a calibration has been completed. The calibration will be stored
until a new calibration is performed.
7. For a two- or three-point calibration, repeat Steps 1-5.
8. The meter should be calibrated before each use to obtain the most
accurate results.