Pressure sensor is displaying zero

Hi there,

Over the years we have gotten some request regarding the pressure sensor showing 0m even though it is in some water,

Our pressure sensors are not depth sensors, but pressure sensors. This means that the offset level of these varies with the barometric pressure.

When the sensor is showing zero it has most likely a negative offset. Of that reason it may continue to show zero until it is submerged enough to meet the negative offset.

When shipping Nortek instruments we put the pressure offset at 1m for DW instruments and 0.2m for others to compensate for some of the changes in the barometric pressure.

In addition there has been a bug in previous software in the pressure sensor offset calibration. The bug is that the software treats the zero reading as zero (not a possible negative value). When you try to offset a sensor showing 0 up to 0.1 it doesn't help you much if the sensor really has a value og -0.5. Then it adjusts it to -0.4 which displays as..... 0

The way around this is to adjust it to a large enough value. Test that the change in the value corresponds as expected when e.g. submerging it in half a meter of water. Set the appropriate offset value the day you deploy it if possible.

-Jonas Røstad-