56-Channel Thermocouple Input Module for OMB-DAQSCAN-2000 Series

The OMB-DBK90 module provides 56 channels of high-accuracy thermocouple (TC) inputs. The OMB-DBK90 is ideally suited for high-channel-count TC applications, with a maximum TC capacity of 896 channels per system. For larger channel-count applications, multiple mainframes can be combined for a maximum channel capacity of 3584 channels. Thermocouples attach to the OMB-DBK90 via mini-TC input connectors, and any TC type can be installed into any channel. Each row of 14 TC inputs has a separate cold-junction sensor to ensure accurate readings.

OMB-DBK90 modules are housed in a rugged all-metal package that can be connected to an OMB-DAQSCAN-2000 and rack-mounted with an optional rack-mount kit. When multiple OMB-DBK90’s are mounted together, a male and female P1 connector on either side of the unit provides all system connections so that only a single cable is required back to the A/D mainframe. For distributed applications, such as throughout the cabin of a vehicle, OMB-DBK90 modules can be mounted as separate units. Up to 20' of cable can be used to connect OMB-DBK90 modules.

Each OMB-DBK90 has a built-in auto-zero channel and a CJC channel. The OMB-DBK90 can measure one TC channel in 3 ms, 14 TC channels in 16 ms, and all 56 TC channels in 61 ms. An OMB-DBK90 based system of 896 channels can be measured in 976 ms. This speed is slower than other OMB-DBK modules to ensure that the TC measurements are accurate, low-noise, and stable. Typical measurement accuracies are better than 0.7°C, with channel-to- channel variation typically less than 0.5°C. If OMB-DBK90 measurements are mixed with measurements from other OMB-DBK options, the other measurements can be made at their standard 5 or 10 µs/channel rate.

Specifications
System Compatibility: Attaches to an OMB-DAQSCAN-2000
System Connector: Male and female DB37 for unit-to-unit mating
and mating with P1 on the acquisition mainframe
TC Connector: Mini-TC connectors
ACOM Connector Type: Pomona model 5936-0
Inputs: 56 differential TC inputs, open TC detection per channel
TC Types: J, K, T, E, S, R, B, N28, N14
Speed: 1 channel in 3 ms, 14 channels in 16 ms, 56 channels in 61 ms
Dimensions:
285 W x 88 D x 52 mm H (11 x 3.44 x 2.05")
Weight: 0.96 kg (2.12 lb)
Power Requirements: 40 mA max from ±15 V; 40 mA max from 5 V; 1400 mW total
Input Impedance: 4 M ? (differential) in parallel with 400 pF
Input Bandwidth: 1 kHz
Minimum Resolution: 0.1°C for all TC types
TC Accuracy: Valid for one year at 25°C ambient (see table)
Operating Temperature:
-30C to 70°C (-22 to 158°F)
Relative Humidity: 0 to 95% non-condensing
Temperature Coefficient of Accuracy for Type T TC: ±0.05°C for every °C away from 25°C
Channel-to-Channel Crosstalk: -90 dB typ (0 to 100 Hz)
DC CMRR: -80 dB typ
AC CMRR: -80 dB typ (0 to 60 Hz)
Maximum Common Mode Voltage: ±10 V
Overvoltage Protection: ±40 V