Tare (Reference Zeroing)
Tare is the device accepting its current attitude as the new zero. In a levelling system this is taken in a position where the vehicle is genuinely horizontal, and all subsequent tilt readings are produced relative to that plane. On the KTS200, tare appears in the specs list as a separate zeroing function.
It is the same logic as zeroing the weight of a container on a scale: the current reading is taken as the reference and the display is zeroed. On a tilt sensor what is zeroed is not weight but the angular offset on two axes.
- When it is taken: after the first installation, when the sensor's position changes, when the control unit is replaced, or when a persistent difference appears between the display and an independent measurement.
- How it is taken: bring the vehicle level on two axes with an independent inclinometer, wait until the movement settles, then issue the tare command.
- When it is not taken: while the vehicle is tilted. A tare taken in a tilted attitude permanently declares that tilt to be the correct plane and repeats the same error at every levelling.
A wrong tare is the cause of the most common field complaint, the system finished levelling but the vehicle is still tilted. In such a case, first retract the jacks, bring the vehicle level using an independent measurement and repeat the tare procedure. Tare is a calibration procedure; it is repeated not at every camp but only when the reference has been disturbed.
Context in which this term is used: Guide to automatic RV levelling