Thermo Fisher Scientific CyberScan pH 1100/pH 2100 - Manual (Page 11)

Instruction Manual pH 1100/ 2100
11
3 P H CALIBRATION & MEASUREMENT
3.1 pH calibration
This meter is capable of up to 5 point calibration with selectable buffer sets (USA, NIST, Bf1, Bf2 or any 5 custom buffers
of your choice). The meter retains stored pH calibrations even when turned off. For best accuracy, we recommend that
you perform at least a 2-point calibration using buffers that bracket (one above and one below) the expected sample
range. A single point cal is possible only at the offset points namely 7.00 or 6.86. For custom buffer sets, you must
perform at least a 2 point calibration.
Selectable buffer sets:
USA: 1.68, 4.01, 7.00, 10.01, 12.45
NIST: 1.68, 4.01, 6.86, 9.18, 12.45
Bf1: 1.68, 4.01, 6.86, 10.01, 12.45
Bf2: 1.68, 4.01, 7.00, 9.18, 12.45
Any 5 user selected custom buffers
To select which buffer sets you wish to use see Section 10.2.2: Program pH Buffer Setup: P1.0 in the pH/Temp setup
mode (page 30).
When you recalibrate your meter, old pH calibration points are replaced on a point by point basis. For example, if you
previously calibrated your meter at pH 4.01, 7.00, and 10.01, and you recalibrate at pH 7.00, the meter retains the old
calibration data at pH 4.01 and pH 10.01. To view current calibration points, see Section 10.2.8: Program pH Cal Data
P1.6 in the pH/Temp setup mode (page 35).
If you choose to recalibrate to only 1 or 2 pH values, the older calibration values you do not calibrate to will remain stored.
These old stored calibration values may cause accuracy loss when your readings are close to the old values. To clear old
calibration data, reset the meter as shown in Section 10.2.9 Program pH Cal Reset: P1.7 in the pH/Temp setup mode
(page 36).
3.1.1 Automatic Temperature Compensation (ATC)
If you will be taking pH measurement using Automatic Temperature
Compensation (ATC), you must perform your pH calibration with
ATC temperature probe attached. Attach the temperature probe to
the rear of the meter. The ATC mode annunciator shows on the
display. See Figure 11. Insert the probe into the pH buffer solution
along with your pH electrode.
If manual temperature compensation is preferred, do not plug a
temperature probe into the meter. The MTC mode annunciator
shows on the display. See Figure 12. The default manual
temperature compensation is 25.0°C. To change the manual
temperature compensation default, see Section 9 Temperature
Calibration for instructions (page 26). 7.179pH 25.3 C ATC
Jan 18 2002 08:46:25 °
7.179pH 25.3 C MTC
Jan 18 2002 08:46:25 °
Figure 11
Figure 12