Fluke 7341 User Manual page 67

because of the increased response time.
The proportional band width is easily adjusted from the bath front panel. The width may
be set to discrete values in degrees C or F depending on the selected units. The optimum
proportional band width setting may be determined by monitoring the stability with a
high resolution thermometer or with the controller percent output power display. Narrow
the proportional band width to the point at which the bath temperature begins to oscillate
and then increase the band width from this point to 3 or 4 times wider. Table 9-2 lists
typical proportional band settings for optimum performance with a variety of fluids at
selected temperatures.
Table 9-2. Typical Proportional Band Settings for Various Fluids
Fluid
Water
Water
Eth-Gly 50%
Eth-Gly 50%
Eth-Gly 50%
Oil 200, 10cs
Oil 200, 10cs
Oil 200, 10cs
Oil 710
The proportional band adjustment may be accessed within the secondary menu. Press
"SET" and "EXIT" to enter the secondary menu and show the heater power. Then press
"SET" to access the proportional band.
S E
+
12 Pct
S
Pb=0.101C
To change the proportional band press "UP" or "DOWN".
D
Pb=0.060C
To accept the new setting and access the cutout set-point press "SET". Pressing "EXIT"
will exit the secondary menu ignoring any changes just made to the proportional band
value.
S
Temperature
30°C
60°C
35°C
60°C
100°C
35°C
60°C
100°C
200°C
Access heater power in secondary menu
Heater power in percent
Access proportional band
Proportional band setting
Decrement display
New proportional band setting
Accept the new proportional band setting
Proportional Band
0.31°C
0.31°C
0.31°C
0.31°C
0.4°C
0.6°C
0.6°C
0.6°C
0.4°C
Controller Operation
Proportional Band
Stability
±0.003°C
±0.003°C
±0.005°C
±0.005°C
±0.010°C
±0.004°C
±0.004°C
±0.004°C
±0.008°C
9
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