Taking redundant level measurements is an important precautionary tactic to prevent spills in the event of sensor failure. While we expect our sensors to last a long time, they will eventually fail – as will any sensor from any manufacturer.
Failure doesn’t necessarily mean the sensor is completely broken. It may be that the sensor needs recalibration, or that environmental factors have caused inaccurate readings. Each sensor is designed with features to avoid this, but having another sensor in place, preferably of another type/technology, can ensure that sensor failure does not lead to disaster.
Eric Thompson, Regional Sales Manager at APG, gives a few examples of when redundant tank level measurement is useful:
- Lift Stations – Let’s say that everyone on the block does their wash at the same time. The soapy water reaches the lift station at the same time. This causes the lift station to foam up from the soap. If a single ultrasonic were installed, the foam would disrupt the sensor, absorbing its signal, and the lift station would overflow. With a high alarm float switch installed, the pump would still activate and prevent a spill – and the resulting EPA fines.
- Tank Agitation – If an agitator is used to mix the contents of a tank, an ultrasonic or radar sensor may see the agitator as the level goes down. The agitation can also produce waves, causing a false reading. A pressure transducer can be installed on the bottom of the tank and will not be affected by the agitation in the tank.
- Oil Production Tanks – When the product in the tank would have environmental effects if the there were an overflow, redundant level measurement is particularly important. This would be bad for the environment and result in high costs to clean up the spill. It makes financial sense to have redundant sensors in case one just quits working. Oil production tanks are generally spread out over a large geographic area, making it more difficult to respond to an overflow.
- High Value Product – In these situations, it is best to have redundant sensors to prevent loss in revenue. The cost of the “extra” sensor is far less than the cost of one overflow.
There are many scenarios that call for a redundant tank level sensor. When it comes right down to it, you are better safe, than sorry. Overflows can cause hazardous conditions for workers, environmental disasters, clean-up costs, fines, and even substantial loss in revenue.
Are you wondering if your tank should have a redundant level sensor? Feel free to talk to one of our experts, or use the comments section below. Ever been saved by a redundant level sensor? We’d love to hear about it!