Thermo Fisher Scientific Alpha pH 500 - Manual (Page 14)

10
5.2 pH Calibration
A complete 2-point CAL is required for this Transmitter. If Calibration is aborted
after 1st calibration point, transmitter reverts to previous Calibration data.
1. Rinse probe thoroughly with de-ionized water or a
rinse solution. Blot excess liquid.
2. Dip probe into calibration buffer. End of probe
must be completely immersed into buffer. Stir
probe gently to create a homogeneous sample.
3. From pH MEAS mode, press CAL to enter pH
calibration mode. CAL indicator will be shown.
Primary display will show measured reading while
secondary display will indicate the pH standard
buffer solution.
4. Press ▲ or ▼ keys to select either pH 7.00 (USA)
or pH 6.86 (NIST) standard buffers. This is the first point, Offset
calibration.
5. Wait for measured pH value to stabilize. Press
ENTER to confirm calibration. Transmitter is now
calibrated to current buffer.
6. Rinse probe with de-ionized water or rinse
solution, and place in next pH buffer (pH 4.01,
pH 9.18 or pH 10.01).
7. Repeat steps 5 and 6.
8. Upon successful Calibration, transmitter displays
Slope (primary display, in mV) and Offset
(secondary display, in pH) of electrode.
9. Press ENTER to return to MEAS mode.
Transmitter has been calibrated. Rinse electrode
and proceed with measurements.
NOTES:
To exit from pH calibration mode without confirming calibration, press ▲ and ▼
keys together.
If selected buffer value is not within
 1.0 pH from measured pH value: electrode
and buffer icon blink and ERR annunciator appears in lower left corner of display.
CAL
HOLD
pH
READY
pH
CAL
HOLD
pH
READY
pH
CAL
HOLD
pH
READY
pH
CAL
HOLD
pH
mV