Why does the industrial thermometer from SIKA have a V-shaped casing?
Because in this way, the glass insert which is inserted in a recess is protected against mechanical impact without a sophisticated box casing.
Why aren’t there any more high-grade industrial thermometers?
Because from +300 °C, a thermometer filling is required whose boiling point is higher. Blue kerosene-based filling liquid would start to boil.
What is the active length?
In the case of a gas filled dial thermometer, this is the “gas tank” at the tip of the immersion tube. The active length depends on several factors, such as the immersion tube diameter, measuring range, etc.
What is an immersion tube?
That is the part of the thermometer which is “immersed” (screwed or welded) in the process.
What is a protection tube?
This is an additional protection tube which is initially screwed or welded in the process, into which the immersion tube of the measuring device is screwed or inserted.
What is the accuracy class of a thermometer?
It depends on the measuring system. Dial thermometers are divided into classes (error limits depending on the display range) according to DIN EN 13190, the accuracy of glass thermometers is defined in DIN 16195 (not in classes). The deviation depends on the measuring range.
How strong is the influence of the ambient temperature on thermometers?
The influence of the ambient temperature is higher in the case of measuring systems with fillings (gas or liquid), as the effect of the ambient temperature can only be minimised by submerging the majority of the thermometer filling in the process (vessel in the immersion tube contains the majority of the thermometer filling or a bimetal compensation in the case of the gas-filled dial thermometers). Due to their measuring system, bimetal thermometers or temperature sensors aren’t influenced by the ambient temperature so much.
How is l1 measured?
Always including the connection thread, i.e. from below the sealing collar on the hexagon to the end of the immersion tube.
What happens if the liquid in the thermometer breaks up into sections?
In this case, a separation of the thermometric column occurs, which is primarily caused by rough handling during transport or due to improper installation. In minor cases, the sections can be put back together, while serious cases indicate a broken glass insert.
What action should be taken if the column is separated?
There are various ways to put the column back together. For example, you can heat the thermometer very carefully (caution with a naked flame - in the event of overheating, the glass insert will burst!), or you can also shake it like you would a medical thermometer. A detailed guide can be requested from us.
Why must an industrial thermometer not be installed upside down or in horizontal position?
Because this can lead to a separation of the thermometric column.
Why is the casing of some pointer-type measuring instruments filled with a liquid?
The filler material, consisting of silicone oil or glycerine, dampens vibrations and impacts, which can influence the instrument via the process. The pointer movement is also protected against damage, and pointer flutter is reduced.
Why is the casing of the pointer-type measuring instrument not completely filled with silicone oil or glycerine?
So that the filler material is able to expand at different ambient temperatures and the casing does not leak due to overpressure.
When is a protection tube required?
At high temperatures or pressures, when working with aggressive media or high flow velocities and in the case of impurities or foreign bodies in the medium to be measured. Also, if the process is not to be emptied when the measuring instrument is replaced. In these cases, the measuring instrument can be installed in an additional protection tube.
When should multi-part protection tubes be used and when should protection tubes made from solid material be used?
If the protection tube is only designed to seal the process so that the measuring instrument can be changed, a simple multi-part protection tube is sufficient. At higher pressures, protection tubes made from solid material are more appropriate.
What material should the protection tube be made from?
This depends on the medium and the material in the pipeline. In the case of protection tubes designed for welding, the material of the protection tube and the pipeline should match.
Are industrial thermometers with a brass immersion tube suitable for potable water?
Our industrial thermometers do not have any explicit certification. We can confirm, however, that we only use brass that is suitable for drinking water (e.g. CW617N-DW) when manufacturing immersion tubes and protection tubes that come into contact with media.