Two-Point Adjustment With Setpoint Entry; Temperature Compensation - Ahlborn ALMEMO 710 Operating Instructions Manual

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12.2.4 Two-point adjustment with setpoint entry

Two-point adjustment can also be performed on other sensors. After zero-
point adjustment (s. 12.2.2) ´Setpoint adjustment´ should be selected and the
´Setpoint´ entered; the channel will then be adjusted. The correction factor is
calculated automatically at the touch of a button and stored as factor on the
sensor connector.
1. Zero-point adjustment
Bring sensor to zero status (icy water, unpressurized, etc.),
Zero-set measured value by means of ´Adjustment´. (see 12.2.2)
2. Final value correction
Bring sensor to a defined setpoint (boiling water, a known weight, etc.).
Measured value
With ALMEMO
order to simulate the check value. (see Manual 3.6.2)
Touch on the measured value, in selection box select ´Setpoint adjustment´,
enter the setpoint and ´Adjust channel´.
The measured value shown should then be the setpoint. 0.0
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If the sensor is locked at level 4 the correction factor is programmed as
´Factor´; if the sensor is locked at level <= 3 or temporarily unlocked,
the correction factor is programmed as gain correction. (see 13.2.10)
For a genuine two-point adjustment involving no zero-point the wizard ´Two-
point adjustment´ is available. (see 14.3)

12.2.5 Temperature compensation

Sensors whose measured values depend heavily on the temperature of the
measuring medium usually incorporate their own temperature sensor and the
device performs temperature compensation automatically. (see 13.2.13 Mea-
suring range list ´with TC´)
However, dynamic pressure probes and pH probes are also available without
their own integrated temperature sensor. If the temperature of the medium de-
viates from 25°C the following measuring errors must be considered:
e.g. Errors per 10 °C:
Dyn. pressure: approx. 1.6%
pH probe: approx. 3.3%
To perform temperature compensation on a probe of this type there are sev-
eral possibilities.
1. Using an external temperature sensor program control character ´*T´ in the
channel designation. (see 13.2.1)
2. Or enter the approximate temperature manually in ´Device settings´  ´De-
vice compensation´  ´Temperature´. This value is then used for all sensors
with temperature-compensation. This can be checked in ´Settings´  ´Chan-
nel functions´  ´Channel compensation´. (see 13.2.14)
Measured value correction and compensation
® force transducers switch the calibration resistor on / off in
Compensation range
-50 to 700 °C
0 to 100 °C
ALMEMO
0.0 098.7 °C
Setpoint 100.0 °C
100.0 °C
Sensors
NiCr-Ni
Ntc or Pt100
® 710 43