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Bar30 Pressure sensor probelms with temperature


(Tina Danielsen) #1

Hello
We have used the Bar30 Pressure sensor in a under water camera to measure both temperature and pressure, the depth is between 1-15 m. We have also some other cameras which have a temperature sensor which are more accurate. The Bar30 Pressure sensor shows a difference around 6 degrees from this more accurate temp sensor.
We tested the Bar30 sensor in air before we put it in the water, and then it was showing the right temp. Do you have any idea what is wrong?
We are using a raspberry pi with python.
Are there any way to calibrate the sensor?

Thank you in advance


(Jacob) #2

Can you give us more information about the other temperature sensors?
Are the other sensors making contact with the water/air in the same way as the Bar30?
Is the Bar30 measuring higher or lower temperatures?

The Bar30 sensors are factory calibrated by the manufacturer (Measurement Specialists), and in our experience, they perform to their specification.


(Tina Danielsen) #3

Hei
It shows 6 degrees more than the Celsius Fast-Response sensor from blue robotics. This sensor is in another camera, which also is in the water at almost the same place.

Today we put a new camera in the water with the bar30 pressure sensor, this camera also show the same offset.

The 30bar sensor shows around 15 degrees, while the celsius fast-response sensor shows around 9 degrees. We know that the temperature cannot be 15 degrees in this time of year.

We have the camera in salt water.


(Tina Danielsen) #4

I found out what was wrong. We had set C6 in the script to be a constant value 12000 in stead of the the value from the bus. My co-worker said that was described in a commit message in github.

Thank you for your time.


(Jacob) #5

@tinadani Thanks for following up. Are you using our github code? Is there a problem with it?

Or are you using your own program?