Ahlborn ALMEMO 2390-5, Руководство по эксплуатации

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Limit values and alarm
Per measuring channel two limit values can be set (1 maximum and 1 mini-
mum). In the event of one of these limit values being exceeded relay output
modules actuate the appropriate alarm contacts. Hysteresis is set by default to
10 digits but can also be adjusted. The exceeding of a limit value can also be
used to start or stop measured value recording and data logging.
Sensor locking
All sensor data stored in the connector EEPROM can be protected by means of
a graduated locking function against undesired access.
MEASUREMENT
For each transducer up to four measuring channels are available; i.e. it is also
possible to evaluate double sensors, individually scaled sensors, and sensors
with function channels. It is possible using the keypad to move from one mea-
suring channel to the next successively forwards or backwards. The selected
measuring point is scanned at a conversion rate of 2.5 or 10 measuring operati-
ons per second; the measured value is calculated and output to the display
and, if available, to an analog output.
Measured value
The measured value for the selected measuring point is shown continuously
with auto zero and, optionally, with measured value correction or scaling.
With most sensors, sensor breakage is detected automatically (except for con-
nectors with shunt, dividers, or additional electronics).
Measuring functions
With some sensors, in order to achieve optimal measured value acquisition,
certain special measuring functions are required. Cold junction compensation
is provided for thermocouples; temperature compensation is provided for dyna-
mic pressure, pH, and conductivity probes; and atmospheric pressure compen-
sation is provided for humidity sensors, dynamic pressure sensors, and O2
sensors. On infrared sensors the parameters for zero-point correction and gain
correction are used as the background temperature and the emissivity factor.
Analog output and scaling
The displayed measured value can, by means of analog start and analog end,
be scaled in such a way that the measuring range thus defined covers the full
analog output range (2 V, 10 V, or 20 mA).
Maximum and minimum values
For each measuring operation the maximum value and minimum value are
acquired and saved to memory. These values can then be displayed, printed
out, or deleted from memory.
Average value of a channel
Averaging can be performed per selected channel for the purposes of signal
smoothing, either over a certain period or over single measurements.
6 ALMEMO
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2390-5
Functions