Interface modules to support E, J, K, R, S, T thermocouples in both 16-bit and 24-bit operations are available. The temperature modules utilise Class B RTD CJC (Cold Junction Compensation) to correct the input signal from the sensor to give the true hot junction temperature.

Each thermocouple module design has been optimised to ensure that the correct CJC correction matches the operating characteris¬tics for the specified sensor. The C7C circuit is mounted adjacent to the terminal connection and corrects the thermocouple signal at the interface to the instrument. The instrument is capable of providing temperature measure¬ments comparable to those achieved using thermal interface blocks.

Part Numbers:
NPAI24-TC-B NPAI24-TC-C NPAI24-TC-E NPAI24-TC-K
NPAI24-TC-N NPAI24-TC-R NPAI24-TC-S NPAI24-TC-T

NPAI16-TC-B NPAI16-TC-C NPAI16-TC-E NPAI16-TC-K
NPAI16-TC-N NPAI16-TC-R NPAI16-TC-S NPAI16-TC-T

NetPod supports a range of interface modules suitable for use in the measurement of absolute temperature using a range of RTD (Resistive Temperature Device) sensors. Each RTD interface contains integrated signal conditioning, sample rate following anti-alias filters, individual Sigma Delta ADC and opto-isolation

The RTD sensor modules can be supplied for use in 2, 3 and 4 wire circuits. The 4 wire technique (see fig. 5) uses a current source together with an individual ADC providing the most accurate method using an RTD sensor to measure temperature. The ADC contained within the RTD module only measures the voltage drop across the sensor and is insensitive to losses caused by the lead resistance. The RTD requires only 250 1tA of driver current, so the self heating effect within the sensor is minimised, ensuring the highest possible accuracy.

Part Numbers: NPAI24-RTI NPAI16-RTI

In order to enable the instrumentation to be used for control operations as well as for monitoring analogue signals, a series of control modules have been developed. These control modules can be used to switch power circuits by employing both solid state triacs or relay units, and also to drive and to process most kinds of digital control signals. Standard logic levels, as well as high voltage signals, can be monitored and controlled. Some of the modules available are:

·	Triac-Solid state zero crossing detector, power switching unit.

·	TTL Digital Output Port.

·	TTL/High Voltage digital input port. Jumper selectable options.

·	Relay switch unit.

Part Numbers:
Digital Inputs - NP4209-DIO NP4210-JIO
Digital Outputs - NP4213-DIO NP4211-RLY NP4212-TRC1
NP4212-TRC2 NP4501-ACL