2.4
Calibrating the Analog EZ Modulevel
The Analog EZ Modulevel must be calibrated for each
unique application. It may be calibrated in service or on
a bench calibration stand. Bench calibration provides a
convenient way to set up the transmitter before going to
the tank site to complete the installation. Bench calibra-
tion, however, does not compensate for elevated process
temperatures.
For convenience during the calibration of a blind transmit-
ter, a DC milliameter may be connected to terminals (M+)
and (M-) in the junction box, see Figure 5 on page 6.
2.4.1 Direct Acting Field Calibration
1. Bring process up to operating temperature.
2. Unscrew and remove protective covers from zero and span
controls. See Figure 13.
3. Rotate the span control counterclockwise fully, approxi-
mately 20 turns.
4. Rotate the zero control counterclockwise fully, approxi-
mately 20 turns.
5. Establish liquid level at the desired 4 mA (0%) level on the
displacer.
6. Adjust the zero control until the output signal is 4.00 mA
(0% on transmitter with analog meter).
7. Replace cover on zero control.
8. Establish liquid level at the desired 20 mA (100%) level on
the displacer.
9. Adjust the span control until the output signal is 20.00 mA
(100% on transmitter with analog meter).
In the case that 20 mA (100%) level cannot be established:
10. After setting the zero point, establish liquid level as close to
the 20 mA level as possible.
11. Adjust the span control until the output signal corresponds
with the % of actual level (e.g. 80 % level should equal (20
mA – 4 mA) x 80% + 4 mA = 16.8 mA).
12. Replace cover on span control.
Desired
Level Range
(Direct Acting)
Desired
Level Range
(Reverse Acting)
Zero and Span Controls
Replace Covers
After Calibration
100% Level,
20 mA Output
Zero Level,
4 mA Output
Bottom of Displacer
100% Level,
4 mA Output
100% Level,
20 mA Output
Figure 13
Analog EZ Modulevel
Field Calibration
10
48-618 ES/EZ Modulevel Displacer Level Transmitter (Top Hat Assembly Design)
