Special measured quantities, Linearization, Multi-point calibration
tion the measured values between these points are interpolated on a linear ba-
sis. When correcting non-linear sensors (e.g. with Pt100 or thermocouple sen-
sors) initially the original characteristic is considered; and only then are the de-
viations interpolated on a linear basis and inserted.
If a channel with a characteristic is deactivated or programmed with a different
quantity, the characteristic can subsequently be reactivated by restoring the
special quantity using command 'B99'.
Other information that can be entered in the extended connector includes the
order number, the serial number, the date of the next calibration, and the cali-
bration interval. In networked systems the calibration intervals can thus be mo-
nitored automatically.
12. TROUBLE-SHOOTING
The ALMEMO
®
809 measured data acquisition module can be configured and
programmed in many different ways. This system is suitable for connecting a
wide variety of very different sensors, additional measuring instruments, alarm
signaling devices, and peripheral equipment. Given these numerous possibili-
ties the device may in certain circumstances not behave quite as expected.
The cause of such unexpected behavior is not usually a device defect; often
the cause is incorrect operation by the user, an invalid setting, or unsuitable
cabling. In such event try to pinpoint and clear the problem with the aid of the
following tests.
Error:
No or all LEDs light up; keys do not react.
Remedy
Check the power supply; charge the battery; switch off and then on
again; if necessary re-initialize (see 7.4)
Error
Measured values are incorrect.
Remedy
Check all the channel programming very carefully, especially the
base value and zero-point (sensor programming and special functi-
ons).
Error
Measured values fluctuate unexpectedly or the system hangs in mid-
operation.
Remedy
Check the cabling for any inadmissible electrical connections. For
sensors with their own integrated power supply check element flag 5.
see 8.5 Unplug any suspicious sensors. In its place connect a hand-
held sensor in air or phantom mode (for thermocouples short-circuit
A-B, for Pt100 sensors use 100Ω resistor) and check. Connect the
sensors again one at a time and check successively. If a fault per-
sists for any one connection, check all wiring; if necessary, insulate
the sensor and eliminate interference by using shielded or twisted wi-
ring.
Error
Data transmission via the interface does not function.
ALMEMO
®
809
27
