Ectron 1140A - Precision Voltage Source (Copper Output); Thermocouple Meter (Alloy Input); Precision Voltmeter (Copper Input); Thermocouple Simulator (Copper Output)

Theory of Operation
Precision Voltage Source (Copper Output)
The general equation for the Model 1140A when it is used as a precision linear voltage source in
the copper mode is
V
OUTPUT
= V
SOURCE
+ V
OFFSET
,
where V
OUTPUT
is the voltage produced at the terminals, V
SOURCE
is the user-specified voltage shown
on the display, and V
OFFSET
is the offset voltage set in the OUTPUT → COPPER VOLTAGE OFFSET
menu.
Thermocouple Meter (Alloy Input)
The general equation for the Model 1140A when it is used to measure temperature using a
thermocouple as its input is
T
METER
= T
INPUT
− T
OFFSET
− T
AZ
,
where T
METER
is the measured temperature shown on the display, T
INPUT
is the theoretical
temperature of an ideal thermocouple connected to the terminals, T
OFFSET
is the thermocouple
offset set in the THERMOCOUPLE → THERMOCOUPLE OFFSET menu, and T
AZ
is the autozero
offset temperature (if autozero is enabled).
Precision Voltmeter (Copper Input)
The general equation for the Model 1140A when it is used as a precision voltmeter is
V
METER
= V
INPUT
− V
OFFSET
− V
AZ
,
where V
METER
is the measured voltage shown on the display, V
INPUT
is the input voltage applied at
the terminals, V
OFFSET
is the offset voltage set in the OUTPUT → COPPER VOLTAGE OFFSET
menu, and V
AZ
is the autozero offset voltage (if autozero is enabled).
Thermocouple Simulator (Copper Output)
The general equation for the Model 1140A when it is used as a precision thermocouple voltage
source in the copper mode is
V
OUTPUT
= f
cn
(T
SIMULATED
) − f
cn
(T
REFJCN
) + f
cn
(T
OFFSET
),
where V
OUTPUT
is the voltage produced at the output terminals, T
SIMULATED
is the equivalent
temperature of the simulated thermocouple, T
REFJCN
is the temperature of the simulated reference
junction set in the THERMOCOUPLE → REF JCT TEMP menu, and T
OFFSET
is the offset temperature
set in the THERMOCOUPLE → THERMOCOUPLE OFFSET menu.
Thermocouple Meter (Copper Input)
The general equation for the Model 1140A when it is used to measure emf’s in terms of
temperature in the copper mode is
T
METER
= T
INPUT
+ T
REFJCN
+ T
AZ
+ T
OFFSET
,
where T
METER
is the measured temperature shown on the display, T
INPUT
is the theoretical
temperature of an ideal thermocouple connected to the terminals, T
REFJCN
is the temperature of the
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