The Model 10A10-4 is a precision conditioner designed for TC-based temperature measurements requiring high input isolation. With built-in reference-junction compensation, it accepts up to four independent temperature signals from Types B, E, J, K, R, S, and T Thermocouples. Any desired mixture of these thermocouple types is permitted. Sensors may be grounded or ungrounded, in any desired mix. An amplifier per- channel design with chopper stabilization and active low-pass filtering allows high-speed scan switching of high-level, stabilized signals per channel.
All four 10A10-4 inputs are transformer-isolated, so that sensor-to-chassis and/or sensor- to-sensor common-mode voltages as high as 1500 V-DC can be accommodated at DC or low frequencies without damaging the instrument or perceptibly affecting measurement accuracy (at 60 Hz, the common-mode voltage can be as high as 1000 V-AC (rms)). During operation, appropriate reference-junction compensation, real-time digital linearization, and engineering-unit scaling are automatically applied by the System 10 Central Processor for each type of thermocouple used. Detection of “open” thermocouples is also provided, as explained in Section 3.a. The Model 10A10-4 includes a rear-panel connector block with screw terminals for direct attachment of TC leads (which cannot be soldered).
The same connector accommodates all TC types. Since the connector assembly also contains a dual-bead precision thermistor for measurement of the reference-junction temperature, no external cold junction is required—although the user may supply his own Controlled Ambient Temperature Zone for reference-junction compensation, if desired. The reference-junction-corrected temperature is made available to the Central Processor through the Model 10A11 Thermocouple Output Processor Card. The purpose of the 10A11 is to proportion and sum the cold-junction reference signal and the amplified TC signal of each channel for presentation to the system's Analog Signal Bus. One 10A11 must therefore be installed in every System 10 A-card rack containing one or more Model 10A10-4's.