# Bar30 depth sensor calibration

**URL:** <https://discuss.bluerobotics.com/t/bar30-depth-sensor-calibration/2070>\
**Category:** Sensors\
**Created:** [January 25, 2018, 4:29pm UTC](https://discuss.bluerobotics.com/t/bar30-depth-sensor-calibration/2070 "2018-01-25T16:29:10Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![kms487](https://avatars.discourse-cdn.com/v4/letter/k/47e85d/32.png) [@kms487](https://discuss.bluerobotics.com/u/kms487)\
**Post date:** [January 25, 2018, 4:29pm UTC](https://discuss.bluerobotics.com/t/bar30-depth-sensor-calibration/2070/1 "2018-01-25T16:29:10Z")

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Hi there. I’ve been trying to use a series of bar30 depth sensors to continuously monitor the depth of water in a bucket with an arduino. Each time I turn on the arduino the sensor gives a different depth, usually +/- 10 cm off. I haven’t found a way to calibrate or equilibrate the sensor with air pressure. The depths I seek to measure are pretty small, and 10cm is way off compared to the accuracy the sensor is rated to. How do I get calibrated or more accurate readings?

Thanks,  
Karly

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**Author:** ![Mikxie](https://avatars.discourse-cdn.com/v4/letter/m/5fc32e/32.png) [@Mikxie](https://discuss.bluerobotics.com/u/Mikxie)\
**Post date:** [January 25, 2018, 7:25pm UTC](https://discuss.bluerobotics.com/t/bar30-depth-sensor-calibration/2070/2 "2018-01-25T19:25:54Z")

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Either program the arduino to zero the measurement before submerging the sensor or use an extra sensor in air to compensate for ambient pressure.