TEMPERATURE SENSING FOR MEASUREMENT AND CONTROL

Introduction

Status Instruments Ltd provide a complete range of sensors for temperature measurement. Our sensors include PLATINUM RESISTANCE TEMPERATURE DETECTORS, THERMOCOUPLES and THERMISTORS.

Our experience has enabled us to offer a comprehensive range of styles to provide the ideal sensor for every application and all manufactured under our ISO 9001 quality procedures. Complete sensor assemblies may be ordered by simply specifying the respective order code for each component required. Unless you specifically request that the components are to be supplied separately, we will assemble the components into a complete unit.

Intrinsically safe assemblies

Complete sensor and transmitter assemblies can be supplied which have been manufactured in accordance with EECS (BASEEFA) I.S. Certificate No. Ex832361 Class EEx ia IIC T5. Please specify when ordering if the I.S. approved assembly is required or just the transmitter. For further details see application section.

Sensors qualifying as simple apparatus as defined in BS 5345:part 4 are also available.

Sensor sensitivity

This may be defined as the change in sensor output relative to the temperature change it is detecting.

Thermocouples produce a non-linear voltage output proportional to the temperature difference between the Hot or measuring junction and the Cold or reference junction, sensitivities vary typically from about 20µV/°C to 50µV/°C.

Pt100 Platinum resistance sensors change their resistance as a function of temperature. The most commonly used exhibit a 0.385 ohm/°C change.

Thermistors provide a much higher change of resistance with temperature, but have restricted ranges and are very non-linear unless used over narrow temperature spans.

Typical transmitter assembly

Other Termination head styles and configurations can be supplied.

A typical assembly of a Style 3 Sensor fitted with an SCH4 Connecting Head and containing an SEM210 Series Transmitter.

Back