User Guide
37
36
Temperature has an effect on measuring pH with conventional
systems. The calibration buffer solutions are affected by temperature
changes to a lesser degree than normal solutions.
Please refer to the following chart to perform the pH calibration more
accurately:
pHpH
pHpH
pH
VALUES AT VARIOUS VALUES AT VARIOUS
VALUES AT VARIOUS VALUES AT VARIOUS
VALUES AT VARIOUS
TEMPERATURESTEMPERATURES
TEMPERATURESTEMPERATURES
TEMPERATURES
TEMP pH VALUES
°C °F 4.01 6.86 7.01 9.18 10.01
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
32
41
50
59
68
77
86
95
104
113
122
131
140
149
158
4.01
4.00
4.00
4.00
4.00
4.01
4.02
4.03
4.04
4.05
4.06
4.07
4.09
4.11
4.12
6.98
6.95
6.92
6.90
6.88
6.86
6.85
6.84
6.84
6.83
6.83
6.84
6.84
6.85
6.85
7.13
7.10
7.07
7.04
7.03
7.01
7.00
6.99
6.98
6.98
6.98
6.98
6.98
6.99
6.99
9.46
9.39
9.33
9.27
9.22
9.18
9.14
9.10
9.07
9.04
9.01
8.99
8.97
8.95
8.93
10.32
10.24
10.18
10.12
10.06
10.01
9.96
9.92
9.88
9.85
9.82
9.79
9.77
9.76
9.75
For instance, if the buffer temperature is 25°C (77°F), calibrate the
meter to read 4.01 or 7.01 or 10.01 on the display.
If the buffer temperature is 20°C, calibrate it to read 4.00/7.03/
10.06.
If the buffer temperature is 50°C, calibrate it to read 4.06/6.98/
9.82.
FOR WM 8930
Turn the switch to the "SET" position. The display will show the set
value (e.g. 5500 µS/cm).
Using a small screwdriver, first adjust the setpoint through the
COARSE trimmer, then fine tune it to your required level with the
FINE trimmer until the desired set value is displayed
(e.g. 5000 µS/cm).
How to select the dosing direction
Select the direction of dosing through the "CONTROL
SELECT" terminals. To increase the conductivity, short the
"HI" terminal with the common terminal in the middle of
"CONTROL SELECT".
For a dosage to reduce the conductivity short the "LO"
terminal with the common (middle) terminal.
E.g. How to dose conductive solutions
Setpoint = 5000 µS/cm
Measured value = 900 µS/cm
To reach the setpoint you need to dose high conductivity
solutions, therefore short "HI" to the middle terminal of
"CONTROL SELECT".
E.g. How to dose reducing conductivity solution
Setpoint = 5000 µS/cm
Measured value = 7500 µS/cm
To reach the setpoint you need to dose low conductivity
solutions, therefore short the "LO" to the middle terminal
of "CONTROL SELECT".