• What is an immersion sleeve?
• What do I have to pay attention to when choosing the right immersion sleeve? 
• When do I need an immersion sleeve?

What is an immersion sleeve?

Immersion sleeves are usually made of stainless steel, but there are also other materials such as brass or ceramic. They are used when the temperature is to be measured directly in the medium and the temperature probe cannot be inserted directly into the process. The immersion sleeve protects the immersion probe. At the same time, it also makes it easier to replace the immersion probe. If an immersion sleeve is used, the temperature probe can be easily replaced without pressure loss or draining of the medium. Immersion sleeves can be used with both resistance thermometers and thermocouples.

What should I pay attention to when choosing the right immersion sleeve?

Please measure your temperature probe accurately and then select a suitable mounting length and diameter. The mounting length should be long enough to reach the minimum immersion depth. At the same time, the immersion sleeve should also not be too long or too wide, so that the surrounding air cushion remains as small as possible. The probe should strike the bottom during installation.

Please also note that the response times will be somewhat slower if immersion sleeves are used, the use of thermal paste can improve the response times.

This is the best way to proceed:

• First, choose the right type.

  How do you want to install the probe? By means of a compression fitting or should the probe be screwed in? What pressure and temperature should your immersion sleeve withstand?

• Then configure the immersion sleeve to suit your application.

  Select the appropriate inner diameter and mounting length.

• Check whether you still need accessories such as thermal paste.

When do I need an immersion sleeve?

The immersion sleeve fulfills two functions:

Function 1: Protection

The temperature sensor is protected by an immersion sleeve. Loads on the temperature sensor, e.g. from pressure in the process or from flow velocities, are kept away from the temperature sensor or temperature probe, as are aggressive media.

Function 2: simple installation and easy replacement of the temperature probe

Subsequent replacement of the temperature sensor is made much easier by the immersion sleeve. Especially in processes where you would otherwise have to drain the medium or where pressure loss is critical, the use of an immersion sleeve makes sense.

However, if you need a very fast and accurate temperature measurement, you should check whether it may be better to carry out the measurement without an immersion sleeve, because the response time is worsened by the use of the immersion sleeve.

What are the different types of immersion sleeves.
Check their requirements and then select the appropriate type. The following criteria can help:

• Process connection: all our immersion sleeves have a G1/2″ process connection - if you need a different thread size, feel free to contact us.
• Mounting of the probe in the immersion sleeve: 
• Locking screw: We offer immersion sleeves with a locking screw. These are suitable for all immersion and cable probes with a sleeve diameter < 6 mm. Please also choose the material that suits you best. We offer these immersion sleeves made of stainless steel and brass.
• Cable gland: Our immersion sleeves with practical cable gland are suitable for all immersion and cable probes with a sleeve diameter between 3.5 and 6 mm. In addition to the particularly fast, tool-free fastening of the probe, they are also convincing due to the strain relief on the cable.
• Internal thread: For all Screw-in probes with G 1/2″ thread, you can use our immersion sleeve with internal thread. It is particularly suitable for temperatures up to 600 °C and pressures up to 600 bar.
• Outer diameter and mounting length: Once you have found the right type, you can easily configure our immersion sleeves according to your specifications: choose the right diameter and mounting length for your application. We have indicated the outside diameter on each immersion sleeve.