Troubleshooting tank calibration issues

Here’s what to do if you are unable to dial in calibrations on WellAware Tank Level Monitoring devices.

Last Updated: October 11th, 2021

Note: This article assumes you are able to connect to the WellAware Device using the Field App. If you are having problems connecting to the device, read this article. >

If you are repeatedly having trouble getting your tank calibrations dialed in using the WellAware Field App, we’re here to help. Usually, tank calibration issues are caused by one of a handful of problems. Here’s how to make sure your tank calibrations are dialed in.

Tip: Use this guide only if you are repeatedly seeing inaccurate tank level data in WellAware. If you are seeing only small discrepancies (data is off by less than 10 gallons or 1-2% of the tank capacity), then we recommend a simple recalibration

Check your sensor

WellAware uses a very reliable tank level sensor for oilfield applications, but sensors do have a shelf life and will eventually fail, especially in caustic or corrosive liquids. The first step is to make sure your sensor is performing as expected.

Follow these steps to make sure the sensor is working as expected.


Visibly inspect the sensor for damage

Keeping the sensor connected to the WellAware device, remove the sensor from the tank and visually inspect it. Look for signs of corrosion or pitting on the metal sensor body, and look for cracks or splits in the sensor cable.


While the sensor is removed, use a clean rag to remove any gunk or debris from the sensor.

If the sensor shows visible signs of significant damage, replace the sensor. 

Note: Minor wear, discoloring, and/or rust are expected and normal.


Check sensor voltage readings

With the sensor removed from the tank, use the WellAware Field App to check the sensor voltage reading. To do this, follow these steps:

  • Open the Field App and log in
  • Connect to the WellAware device
  • Tap the Tank Application on the device home screen
  • Look for the sensor voltage below the tank graphic

IMG_0520-png IMG_0524-png IMG_0526-png Tank Home Screen - voltage

With the sensor removed from the tank, the sensor reference voltage should be stable within 5% of 1 volt. Voltage readings between 0.95 V and 1.05 V are acceptable. 


If you observe any of the following issues, follow the steps outlined below:


The sensor voltage is at or very near 0.00 V | This indicates that the sensor may be damaged, or has become disconnected. To check if the sensor has become disconnected, follow these steps:

  • Safely disconnect the power source from the WellAware device
  • Open the lid of the WellAware device to expose the wiring bay. If necessary, remove any protective plates, being sure to follow appropriate safety procedures.

Warning: Do not open the WellAware device in inclement weather, as this may damage the electronics.

  • Visually inspect the wiring terminations in the WellAware device, making sure each of the 3 sensor wires is properly seated in the terminal block, and the terminal block is firmly connected to the WellAware device.

wire disconnected terminal block disconnected

Note: It may be necessary to remove the terminal block using a pair of needle-nose pliers to check if the connector pins have been damaged.

  • If the terminal block is disconnected, reconnect it. If the wires have become disconnected, reconnect them and tighten them in the terminal block. Reinstall the terminal block, aligning the wires to the labeled pins as follows:
    • Red: Vs+
    • White: Vi1*
      * Or Vi2 for Tank 2; Vi3 for Tank 3, etc.
    • Black: GND
  • If the connector pins are damaged, please call WellAware Client Success immediately (210) 816-4600 Ext. 2 for a potential workaround.


The sensor voltage is pegged at or near 5.00V | This may indicate a restricted reference tube or a failed sensor. To check the reference tube, see “Check sensor reference tube.”


The sensor voltage continually fluctuates by more than +/- 0.05V | This likely indicates a failed sensor. Remove and replace the sensor.

Caution: Don’t throw your old sensor away! Most WellAware sensors are covered under our equipment warranty and will be replaced at no additional cost. In order to obtain the warranty, the failed sensor must be returned to WellAware under a returned merchandise authorization (RMA). For assistance on returning a sensor, contact WellAware Client Success >.


Check the sensor reference tube

The WellAware sensor uses hydrostatic measurement principles, meaning it measures the “pressure” exerted by the liquid on top of it. To get an accurate reading, it has a reference tube that accounts for and offsets the atmospheric pressure. If this reference tube becomes restricted, crimped, or clamped, it will cause inaccurate level readings.

To check if the sensor reference tube might be affected, follow these steps, observing the sensor voltage in the Field App as you perform them. Check to see if the voltage returns to normal with any of these steps.

  • Visibly inspect the sensor cable from the tank to the WellAware device. Check for and remove any kinks or crimps that might be restricting the reference tube.
  • Safely disconnect the power source from the WellAware device
  • Open the lid of the WellAware device to expose the wiring bay. If necessary, remove any protective plates, being sure to follow appropriate safety procedures.

Warning: Do not open the WellAware device in inclement weather, as this may damage the electronics.

  • Find the sensor reference tube, and check to see if it is crimped, blocked, or damaged.
  • Close and secure the lid of the WellAware device.
  • If removing kinks or crimps restores the proper sensor voltage, reinstall the sensor wiring to eliminate the issue.
  • Loosen the cable gland where the tank level sensor enters the WellAware device.
  • If loosening the cable gland restores the proper sensor voltage, completely loosen the cable gland nut, and then screw it back on. The cable gland should only be hand-tight. Do not “crank down” on the cable gland.

Check the tank

In order for the WellAware device to measure and record accurate tank level readings, the tank must be in good condition and properly installed. Check for any of the following issues with the tank. If you find any of these issues, we recommend that the tank be replaced or reinstalled:

  • Significant tilting or tipping
  • Cracks or leaks
  • Significant warping or bowing

IMG_2939-1These tanks are properly installed, with no significant tilt or warping.

A note on tank grounding

Some plastic oilfield tanks can be susceptible to building up a static charge. This not only causes problems with sensor electronics but also creates a significant safety risk when flammable vapors are present.

WellAware recommends that ALL plastic tanks in the oilfield are grounded. At the very least, tanks that “float” on an enclosed plastic containment, such as that pictured below, should be grounded to avoid static buildup and subsequent discharge.

IMG_2665Tanks like the one pictured above, which sit on closed plastic containments, should be grounded to avoid static discharge.

Clear calibration and create a new calibration

If there are no issues with the sensor or tank, we recommend clearing the calibration and starting a new calibration.

Bad tank data may simply be caused by a poor initial calibration. This critical process captures several important variables that determine the accuracy of any calibration, including the sensor reference voltage, the tank shape, and the tank maximum capacity. Errors in any of these steps will cause issues in ALL subsequent recalibrations.

To clear the calibration and start a new calibration, follow the steps outlined in this article >.

Still having trouble with your tank calibrations. Don’t hesitate to contact WellAware Client Success at or (210) 816-4600 Ext. 2.