The readings seem off

Last update: 19/04/2022
Version:

If you are receiving data that seems wrong, there might be a problem either with the transmitter or the thermocouple. Go through the guides below to solve the problem.

1. Is the transmitter's battery low?

Sometimes, before the transmitter runs out of battery completely, it may start sending data less often or it starts behaving in a strange way. To check if this is the cause of the problem, do the following:

  1. Connect a type K thermocouple to the transmitter.
  2. Log in to your Maturix account (either In-Situ or Precast)
  3. Go to the “Device Manager” tab, located in the left side menu.
  4. Look at the “Battery” column. If you see an icon saying “Consider battery service” (like in the picture below) or the field is blank, it means that the battery is too low. So you will need to replace the old batteries with new ones.

If you have a Gaia 200, you can change the transmitter’s batteries yourself (refer to page 5 in the Gaia Start Guide). If you have an Orbit K, you will need to contact us to coordinate the refurbishment and battery service of your device.

5. If your transmitter’s battery is okay, the problem might be the thermocouple that you were using for the measurements. Move to the next section to read how to check if the thermocouple is the problem.

2. Are the thermocouples okay?

If you see strange drops in temperature/strength or abnormal fluctuations it might be a sign of a damaged thermocouple. The four most common problems with thermocouples are: 

a. The thermocouple ends were not twisted together or the tip was in contact with conducting material.

In order for thermocouples to work correctly, it is necessary that both wire ends are in tight contact with each other. If this is not the case, the temperature readings may be affected. Therefore, when you are assembling your own thermocouples or reusing them, it is important to remember to twist the wire ends.

Other measurement errors might occur because the thermocouple end is in contact with a conductive material such as a rebar. To avoid this problem, you could insulate the end with heat-shrink tubing as in the right-side image below.

b. The polarity of the thermocouple is wrong

If your data looks something like the graph below, where the temperature goes down and the strength does not increase, probably the polarity of your thermocouple is wrong.

To check if you have this polarity problem, open the thermocouple head and look at the poles. The red wire should be connected to the positive pole (+ plus) and the black wire to the negative pole (- minus).

If you find that the wires were connected the wrong way, you can easily correct it by reconnecting them to the right pole. If you reassemble the wires, remember that the wire ends should be placed between the two metal plates. You can use the picture in the section below for reference.

c. The thermocouple is not assembled correctly.

If you have this problem, the data in your graph might look normal for a while but then there might be inexplicable drops or increases in temperature. If you look at the graph below, you will see that the red line illustrates this phenomenon:

Sometimes, the wires are connected to the right polarity but not stripped or placed correctly. For the thermocouple to measure correctly, it is important that the wires are placed between the metal plates and stripped down so no wire can cross from one polarity to the other. 

If the wires are stripped to far down, the wires are likely to touch each other. And if they are assembled on top of the metal plates, the wires from either side might cross to the other causing errors in readings. See the pictures to see what we are referring to.

WRONG

wrong2

RIGHT

right2

If you have this problem, open the thermocouple head and reposition the wires in the correct way (use the right picture as a reference) or replace the thermocouple with another one.

d. The thermocouple is damaged.

If none of the problems above applies to you, you may be facing a damaged thermocouple. To confirm it, connect another type K thermocouple to the transmitter and see if it solves the problem. If after changing the thermocouple the problem persists, contact us for support below. 

Further Questions

If after reading this article, you still have questions contact us for support.

Was this article helpful?
Dislike 0