The Model 1140A provides four calibration functions: precise
simulation of thermocouple signals, precise measurement of
thermocouple signals, generation of accurate dc voltages from
microvolt level to ±11 volts, and measurement of dc
voltages over the same range. The thermocouple simulation and
measurement accuracies are the highest in the industry, affording
a margin of calibration accuracy heretofore unavailable.
Using a high-speed microcontroller, the 1140A offers such unique
features as an autozero function to correct the zero reading
of a non-ideal thermocouple. For repetitive operations, 100
sets of operating conditions can be committed to memory for
future retrieval, including automatic sequencing from one
condition to the next. Using one of the several interfaces,
all functions can be programmed and executed under computer
With an output impedance of less than 0.05 Ω on all ranges,
high accuracy is maintained with an absolute minimum of loading
Alignment and Calibration
Calibration of the 1140A is a simple procedure
that can be completed with a minimum of test equipment. In
fact the majority of the instrument's alignment can be accomplished
with only a short across the front-panel terminals.
Alignment is performed by the instrument’s firmware and the user
is guided by front panel instructions. There are no potentiometers
or other internal controls to adjust. A switch inside the
unit enables the alignment function.
Alignment is carried out in
several steps, allowing alignment of all functions or a
subset to be performed separately. Full alignment calibration
requires a known 10 V reference, a null meter with microvolt resolution,
and a shorting jumper. These accessories are available
from Ectron Corporation.