In the case that 20 mA (100%) level cannot be established:
11. After setting the zero point, establish the liquid level as
close to the 20 mA level as possible (must be more than
50% of the total span).
12. Press ENTER to start 20 mA calibration. The ZERO LED
will light. Loop will go to 22 mA.
13. Press UP to lock in 20mA value. The ZERO LED will go
off. The SPAN LED will be on. Loop will go to 20 mA.
14. Toggle UP and DOWN until the loop signal corresponds
with the % of actual level (e.g. 80 % level should equal
(20 mA – 4 mA) x 80% + 4 mA = 16.8 mA).
15. Press ENTER to confirm the setting. The SPAN LED will
go off. Loop will stay at value chosen in step 14 above.
16. Replace cover.
Note: When calibrating for reverse action (4 mA at high level, 20
mA at low level) step 2 will be establishing high level at the
4 mA level and step 7 will be bringing the level down to the
20 mA level.
3.4.2 Push-button Bench Calibration
The Digital ES II Modulevel can be bench calibrated using
the calibration stand (P/N 31-6107-001) (except units that
have been calibrated for interface service. Bench callibra-
tion cannot be performed on interface models). The fixture
includes an open topped enclosing tube upon which the
transmitter head is mounted and an adjustment rod which
simulates level movement of liquids with various S.G.s.
Bench calibration does not compensate for elevated process
temperatures and must be fine tuned in the field.
To remove transmitter head from control:
1. Disconnect field wiring at the junction box.
2. Loosen the housing base lock screws. See Figure 3 on page 4.
3. Remove transmitter housing cover.
4. Remove c-ring from enclosing tube using snap ring pliers.
5. Slide transmitter on housing base upward until clear of the
enclosing tube.
To install transmitter head on calibration stand, carefully
slide the white teflon spacer and LVDT assembly down
over the open topped enclosing tube. Be certain that both
the LVDT assembly and the housing base are fully seated
on the fixture. See Figure 15 on page 13.
17
48-618 ES/EZ Modulevel Displacer Level Transmitter (Top Hat Assembly Design)
