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Insertion Temperature Sensor with quick release

insertion temperature sensor with quick release TPA-3

The TPA-3 is an insertion type temperature sensor which uses a 3-wire PT100 or PT1000 Platinum Resistance Thermometer (PTR) to BS 1904, for precision temperature measurements.

Insertion Temperature Sensor TPA-3 Introduction

The TPA-3 is an insertion temperature probe, manufactured in 316 stainless steel and utilising a 3-wire PRT to BS 1904 standard.

The TPA-3 has a DIN spec quick release mounting head which allows easy connection to the 3 wire PRT housed into the tip of the sensor. The DIN spec head pushes onto the fitting allowing it be easily attached and removed when the sensor is installed or calibrated. The temperature assembly is manufactured in 316 Stainless Steel with an all-welded construction to food grade standards.

The PT100 or PT1000 Platinum Resistance Thermometer is located in the tip of the stainless steel stem which is filled with our special thermal packing material.

The TPA-3 can be supplied with a compression fitting or manufactured with a welded-on process connector, for use with either our TPP Thermowell or TPP-1 Temperature Pocket respectively.  We offer a range of process fitting sizes for use with either our thermowells or for directly connecting into a process.  The standard size is 1/2" BSP with options for 1/4" BSP or 3/4" BSP, if required.  When supplied with a welded process fitting, the lagging distance is 75mm from the head.

The length of the sensor is 150mm, as standard, and we can manufacture the TPA-3 with a shorter / longer insertion length as required.

The TPA-3 is suitable for measuring the temperature of processes in tanks or in pipework, either screwed directly into the process or through a thermowell or temperature pocket, where the chemical doesn't react with 316 Stainless Steel.

We rate the TPA-3 for measuring a temperature range of -50.0°C to + 250.0°C.

Insertion Temperature Sensor TPA-3 - 3 Wire PRT PT100 / PT1000

Inside the DIN Spec connector is a 4 pin standard socket with a detachable connector, complete with gland.  This allows a 3 wire PRT to be wired into a temperature controller or other instrument which takes an input from a PT100 or PT1000.

As a 3 Wire device, the resistance in the cable that connects the insertion temperature sensor to the instrument is negated by measuring the cable resistance of the third wire. This ensures that the temperature is measured accurately and precisely.

The TPA-3 can be used with a TT100 4-20mA Temperature Transmitter where the TT100 is mounted in a separate enclosure to the TPA-3. This type of installation can be tricky, so please do contact us if you're unsure.

Insertion Temperature Sensor TPA-3 Installation

The TPA-3 is easily installed into a process connector or a thermowell / Temperature Pocket.  When using a compression fitting, the insertion length can be adjusted as required.

If using the TPA-3 with a welded process connector, the standard 1/2" BSP threaded connection has 75mm lagging between the head and the base of the process connector and you should ensure that the temperature sensor is the same size or slightly shorter than the temperature pocket.

Insertion Temperature Sensor TPA-3 Features & Benefits

The TPA-3 is an excellent way of measuring liquid temperature for control or monitoring purposes; whether in process, water treatment and effluent treatment applications.

The 3 Wire PRT is precision device to BS 1904 and can be either a PT100 or PT1000 depending upon the connecting instrument.

The all welded construction makes the TPA-3 suitable for food grade applications and when manufactured with a welded 1/2" boss, securing the TPA-3 into a thermowell, temperature pocket or direclty into a process with a female socket is as simple as possible.

The DIN Spec quick release fitting allows the temperature sensor to be inserted easily into the process with the head fitted afterwards.  The same is true for removal. Remove the head and the whole assembly by simply unscrewing the fixing screw, or compression fitting.

The TPA-3 can be paired with any instrument that takes a 3 Wire PRT input or one of our temperature controllers and is designed to offer the user a long operational life, providing accurate temperature measurements.

TPA-3 Specifications

  • Specifications


    Insertion Temperature Sensor with Quick Release Head

    Model No:- TPA-3

    Range:- -50°C to + 250°C

    Installation:- Process fitting or compression fitting

    Mounting:- Insertion Only

    Head Material:- DIN Spec quick release fitting in GFN

    Sensor Material:- 316 Stainless Steel all welded construction to food grade standards

    Sensor Type:- PT100 or PT1000 to B.S. 1904

    Diameter:- 6mm Ø as standard

    lagging:- 75mm as standard when fitted with a process connection

    Insertion Length:- Standard 150mm 

  • Ordering Information

    Model NumberHead TypeInsertion LengthConnector TypeConnector Diameter
    TPA-3-XX Quick Release Din Connector XX = length in mm  None N/A
    TPA-3-XX-CF025 Quick Release Din Connector XX = length in mm  Compression Fitting 1/4" BSP
    TPA-3-XX-CF050 Quick Release Din Connector XX = length in mm Compression Fitting 1/2" BSP
    TPA-3-XX-CF075 Quick Release Din Connector XX = length in mm Compression Fitting 3/4" BSP
    TPA-3-XX-PF025 Quick Release Din Connector XX = length in mm Process Fitting (Welded) 1/4" BSP
    TPA-3-XX-PF050 Quick Release Din Connector XX = length in mm Process Fitting (Welded) 1/2" BSP
    TPA-3-XX-PF075 Quick Release Din Connector XX = length in mm Process Fitting (Welded) 3/4" BSP

    The standard lagging distance (the space between the Din Connector and the top of the Porcess Fitting) is 75mm. The TPA-3 can be manufactured with a custom lagging distance - please call or message our friendly sales team for more information.


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