Omega CL27 - Manual (Page 35)

33
Model Software Revision
CL23A 6.7
CL24 7.7
CL25 3.7
CL26 5.6
CL27 4.16
(Software revision is marked on a label attached to integrated-circuit U1 on
the mother-board).
"Copper-mode" is a non-compensated mode of operation during which
cold-junction compensation of inputs and outputs is disabled. This permits
the use of copper-wire interconnections between instruments, while avoid-
ing the time and expense of multiple thermocouple-cable hookups. At the
conclusion of calibration verification, cold-junction compensation is re-
enabled, and operation returns to "alloy-mode".
“Alloy-mode” refers to Thermocouple operations; for example, a Type-K
thermocouple is made up of Nickel/Chromium and Nickel/Aluminum alloys.
Referring to the OMEGA Calibrator(s) in TC operation, “Alloy-mode” means
in effect “other than Copper-mode.” In order to make accurate measure-
ments using a thermocouple device one must eliminate erroneous voltage
signals. In “Alloy-mode”, the OMEGA calibrator automatically calculates the
cold-junction compensation for the selected TC type, based on the value(s)
from the ITS-90 table. This feature enables the user to make accurate tem-
perature measurements without making manual calculations for error cor-
rections.
COPPER MODE VERIFICATION PROCEDURE FOR THERMOCOUPLE
FUNCTIONS
Equipment Required:
1. OMEGA Model to be verified.
2. Voltmeter accurate to 1µV resolution.
3. Cable assembly (Fig. 11).
1. Start your calibration with a fresh battery.
2. Press the ON function button to turn the unit on.
3. Select the calibrator mode (“CALIB” on display) by pressing the
CALIB/METER function button.