23
2.4 Allow sufficient time for the display to stabilize. The
instrument will display the mV value of the sample.
If "
OvEr/Undr
”" is displayed, the mV value measured is out
of the “1250/-2000 mV” range. The instrument will display
the correct value once the input mV is brought within
range. It is not necessary to [CLEAR] the instrument.
2.5 The ATC/Temp probe can be used to measure the sample
temperature as required.
pH BUFFERS
The temperature coefficient of pH calibration buffers 4.01, 6.86,7.00,
9.18 and 10.01 are stored inside the instrument. The buffers used to
calibrate the instrument must exhibit the same temperature
characteristics as the stored values.
TABLE 1.
Temperature coefficient of the pH buffers
℃
4.00
6.86
9.18
4.01
7.00
10.01
0 4.01 6.98 9.46 4.01 7.11 10.32
5 4.00 6.95 9.39 4.01 7.08 10.25
10 4.00 6.92 9.33 4.00 7.06 10.18
15 4.00 6.90 9.28 4.00 7.03 10.12
20 4.00 6.88 9.23 4.00 7.01 10.06
25 4.00 6.86 9.18 4.01 7.00 10.01
30 4.01 6.85 9.14 4.01 6.98 9.97
35 4.02 6.84 9.10 4.02 6.98 9.93
40 4.03 6.84 9.07 4.03 6.97 9.89
45 4.04 6.83 9.04 4.04 6.97 9.86
50 4.06 6.83 9.02 4.06 6.97 9.83
