National Instruments NI-9214

The National Instruments NI-9214 is a high-density C Series temperature input module designed to enhance systems with an increased number of thermocouple channels. This module accommodates sixteen thermocouple inputs, complemented by one internal autozero channel for offset error compensation, ensuring precise measurements. It features a sophisticated configuration that minimizes heat gradients and incorporates Cold-Junction Compensation (CJC) sensors located in the terminal block, thus enhancing overall accuracy.

The NI-9214 employs a 24-bit Delta-Sigma analog-to-digital converter (ADC) that operates in scanned sampling mode, supporting a measurement range of ±78.125 mV. It is compatible with various thermocouple types, including J, K, T, E, N, B, R, and S as defined by NIST. Engineered for robust performance, the module provides substantial protection against common-mode voltage variations, with specifications of ±1.2 V between channel-to-common and ±250 V from common to earth ground. The device features impressive common-mode rejection rates of up to 100 dB between channel and common, and 170 dB between common and earth ground in high-resolution mode.

The NI-9214 operates in two modes to cater to different application requirements: high-resolution mode, offering 14.4 Hz bandwidth and 65 dB noise rejection, and high-speed mode, with an 80 Hz bandwidth aimed at optimizing noise rejection for 50 and 60 Hz signals. Overvoltage protection of ±30 V between any two inputs ensures safety for connected devices. Additionally, it boasts a differential input impedance of 20 MΩ and low input noise levels, maintaining RMS values ranging from 220 nVrms to 2.8 μVrms. Temperature measurement accuracy varies between 0.01 °C and 0.48 °C, depending on the thermocouple type and operating mode, while reliable cold-junction compensation is maintained across a wide temperature range.

The module utilizes screw-terminal wiring, adheres to specified torque and gauge requirements, and exhibits IP40 ingress protection. With an operational temperature range of -40 to 70 degrees Celsius, the NI-9214 is well-suited for demanding environmental conditions. Weighing 5.0 oz., this module comes with a three-year warranty, and user and maintenance manuals are available for download. For pricing information, please contact a sales representative.