Burster 9243 - Adjustment and Calibration; Adjustment with a Physical Variable; Adjustment with a High-Precision Voltage Source (also Refer to Chapter 6.6); Adjustment with a Strain-Gauge Simulator

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6.7.1 Adjustment and calibration
The 9243 amplifier module can be calibrated using several different techniques. The device
settings must be checked following adjustment.
6.7.1.1. Adjustment with a physical variable
Application: For all sensors.
Function: Using a scale as an example: Adjust the zero point with the scale in the
unladen state. Then load the scale with a known, reference weight and
set the final value.
Note: The entire measuring chain is calibrated in this case.
6.7.1.2. Adjustment with a high-precision voltage source
(also refer to Chapter 6.6)
Application: For all sensors which generate voltages.
Function: The sensor is simulated by a high-precision voltage source. The
integrated calibration source (5.000 mV) or an external source can be
used.
Note: In the case of strain-gauge full-bridge sensors and potentiometeric sensors, the feed voltage
influences the measurement results. If you want to verify the functionality of the device with
voltage sources, you must measure the sensor feed voltage with a high-precision digital
voltmeter and then calculate the calibration voltage.
IMPORTANT: This method cannot be used to check whether the sensor functions properly.
Suitable calibration devices (e.g. Model 4405, Model 4422) are listed in Section 4.
6.7.1.3. Adjustment with a strain-gauge simulator
In situations where strain-gauge sensors cannot be loaded in accordance with specific
parameters, due to an absence of suitable weights, for example, the required measuring signal
must be generated by a strain-gauge simulator. The irregular characteristic values exhibited by
many strain-gauge sensors can usually not be set precisely by a simulator. In such cases, the
simulator sets the next lower characteristic value. The corresponding voltage at the amplifier
output is calculated as shown in the following example:
Given: A type 8438-100 kN sensor is to be simulated. According to the sensor
specifications, its rated characteristic value is 1.678 mV/V. The required
voltage at the amplifier output for a rated load of 100 kN is U
O
= 10 V.
Wanted: The amplifier output voltage U
OSIM
to be set after a strain-gauge
simulator has been connected.
1
st
step: Set the strain-gauge simulator to the next lower characteristic value, in
this case 1.5 mV/V.
2
nd
step: Calculate the amplifier output voltage to be set if only 1.5 mV/V are
supplied by the simulator instead of 1.678 mV/V by the sensor.
Remember: The 1.678 mV/V from the sensor should generate U
O
=10 V
at the amplifier output.