Multipoint Temperature Sensor Designs

We manufacture multipoint temperature sensor assemblies. We regularly supply Duplex and Triplex assemblies both in thermocouples and pt100 sensors, but we have manufactured thermocouples with up 60 discrete measuring points. Usually these measuring points are in defined positions some distance apart.

Multipoint temperature sensors are often suitable for a number of reasons:

  • Temperatures across a fluid flow need to be known with minimal flow disruption.
  • There are a limited number of access holes designed into a vessel.
  • Measuring points can be duplicated (Signal or System duplication) enabling temperature measurement redundancy  in case of sensor failure.
  • Fluid in a vessel has a limited stirring capability because of viscosity or fixed inclusions within a fluid.
  • A process demands specific multiple temperature location inputs.
  • Over temperature events can spontaneously occur at various points within a vessel. For example, at oxygen injection sites.
  • Cost. One sensor can be cheaper than many individual sensors.

If you are unsure exactly what you need, get in touch and we can help identify your requirements.

Single Sheath Multipoint Temperature Sensors

A high temperature multipoint thermocouple is usually contained within a single outer sheath. The simplest and highest temperature designs have rigid outer sheaths.

A single sheath must be oversize, to accommodate a number of sensors. This can compromise response times and create an averaging effect from sheath conduction.

Examples of single sheath multipoint assemblies made by Peak Sensors include

  • Triplex thermocouple sensors for container glass forehearths.
  • Multipoint Thermocouples for Catalyst Tank Profiling.

Triplex thermocouples are a common multipoint temperature sensor:

Multiple Sheath Multipoint Sensor Assemblies

A multipoint temperature sensor can also consist of many different sensors fixed to a single flange for a single point of entry into a process. We have supplied multipoint thermocouple sensors with up to 60 individual sensors passing through a single flange. This has been done with a double pressure sealing arrangement. The multipoint thermocouple was used in a Vinyl Acetate Monomer (VAM) reaction vessel.

Multipoint sensors rarely allow for the replacement of one measuring point. We can design in some redundancy to allow for individual readings to fail.

Multipoint thermocouples can resemble an ‘octopus’ with many sensors in individual sheaths joined at a single point:

multipoint thermocouple