What would cause the Sensor Error State (SER) to go to 0 on a Connect Tank?

The 'ser' variable, under Data Streams in Device Cloud, stands for Sensor State Error.  This variable can have two states:

0 — sensor error
1 — no error

So what would cause it to go to 0?

The 'ser' data point goes to 0 when a target can't be acquired on the sensor.  This can happen for a variety of reasons:

1. target too close (for SR units the minimum is 4", for MR units the minimum is 12")
2. target too far (for SR units the maximum is 7', for MR units the maximum is 15')
3. interference from some object in the tank (solid, liquid or gas)
4. sensor isn't mounted properly

Here is an example of what 'ser' at 0 looks like:

Note the '0' value under Data.