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Protection Tubes Form 1

Protection tubes form 1 as defined by standard DIN 43 722 are a straight design, are open at one end and equipped with a bottom at the other end. Alternatively this end can also be welded or dished. The open end can be plugged into the connection head of the thermometer and is fastened there with locking screws.

This design type is often used with straight thermocouples. Further details can be found under the corresponding menu item of our website. There you will also find accessories like stop flanges and threaded bushings.

Protection tubes form 1 are available with diameters of 15 mm, 22 mm and 32 mm.

The standard nominal lengths are 500 mm, 710 mm, 1000 mm, 1400 mm and 2000 mm. Other lengths are available on request.

Protection tubes form 1 can be supplied in various materials. Protection tubes made from material no. 1.0305 can be supplied with coatings resp. enamelled.

The ordering code of this product is composed of the component name, design type, diameter, identification letter of the material number and protection tube length. The assignment protection tube length to nominal length can be found in our Product Information "Protection Tubes acc. to DIN 43 722".

Example: Protection tube

Total length
L in mm
Nominal length
U1  in mm
Outer diameter
F1  in mm
Measuring insert
length for connection
head form B in mm
Measuring insert
length for connection
head form A in mm
15 1,2
22 1,2
32 1,2


  • ¹) These protection tube diameters are preferably used for straight thermocouples as per our Product Information 172. A selection of protection tube materials can be found on page 11 of product information 175. 
  • ²) Upon request this protection tube made of material no. 1.0305 (St 35.8) can be coated with different enamellings. The outer diameter will then increase by approx. 2 mm; from the open end approx. 20 mm remain uncoated. 
  • ³) Protection tubes with a diameter of 32 mm can only be fitted with connection heads form A.