Measurement error correction

I have a measurement error. What can I do?

There can be different reasons for measuring errors. If a measurement error occurs, the following possible causes should be checked first. If these sources of error can be excluded, please contact us.


  •  Higher friction forces by damaged roll bearings
  •  Friction by rotary connection or feed-through, e.g. with chill rolls
  •  Contact of the measuring roll with pressure rolls, strippers, or brushes
  •  Drives or brakes are connected to measuring roll
  •  Acceleration and deceleration forces acting at the measuring roll during speed changes
  •  Bending forces in the web when winding and unwinding
  •  The actual mounting position is different from the design
  •  Torque of mounting screws not according to specification
  •  Fixed and floating bearing not correctly mounted
  •  Liquids entered the cavities of the sensors

Why does my amplifier constantly indicate 4 mA or 0 V?


The current output constantly shows 4 mA:

• If a negative voltage is present at the voltage output, the zero point adjustment without measuring load must be carried out again.

The voltage output shows constantly 0V:

• Check the bridge supply voltage
   - Short circuit due to sensor
   - Amplifier defective

• Check amplifier input signal or sensor output signal
   - Sensor is limited in the range of motion
   - Measuring direction of the sensor does not point in the same direction as the actually acting force
   - Sensor defect


Is my sensor defective?


• Connect the unloaded sensor to the amplifier and measure signal voltage

- Correct value: 0 mV
-Values of up to +- 1 mV harmless
-Values up to + 1.6x rated output signal: Sensor overloaded. May be used depending on the load direction
-Values up to + -25 mV: Sensor overloaded. For amplifiers with zero-point adjustment, it may be possible to use them
-Values greater than + -25 mV: sensor defective or incorrectly connected
-Values at half bridge supply voltage: cable break or incorrectly connected


• Input resistance and output resistance without amplifier

-Resistors should be approximately equal, with the input resistance being up to 1.5 times the output resistance
-Typical output resistors are 350 Ohm, 700 Ohm, 1000 Ohm, 1400 Ohm and 2000 Ohm


• Measure resistance between sensor housing and individual wires (insulation resistance) without amplifier

-The resistance must be greater than 10M Ohm