Ahlborn ALMEMO 204, Operating Instructions Manual

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Functions of the ALMEMO® 204
Analog output and scaling
Each measuring point can be scaled by means of analog start and analog end
in such a way that the measuring range thus defined covers the full range of
the bar chart or of an analog output (2 V, 10 V, or 20 mA). At the analog output
the device can output the measured value from any measuring point or a pro-
grammed value.
Measuring functions
To achieve optimal measured value acquisition some sensors require certain
special measuring functions. The new intelligent sensors perform atmospheric
pressure compensation and temperature compensation internally and automat-
ically. With infra-red sensors the emissivity factor can be configured and set.
Measured value smoothing
Measured values of an unstable, fluctuating nature can be smoothed by taking
a sliding average over a number of values programmable from 2 to 99. The
averaging period will depend on the sampling rate and the number of active
channels. However, most D6 and D7 sensors are assigned their own averag-
ing period for all primary channels; this can be set via the sensor menu.
Maximum and minimum values
For each measuring operation the maximum value and minimum value are ac-
quired and saved to memory. These values can then be displayed, output, or
deleted from memory.
Average value
Manual averaging is available per channel over a particular period or cycle or
over a series of individual measuring operations.
Measured value memory
Up to 10 measured values can be saved manually. This data can then be
shown on the display or output via the interface.
5.1.3 Process control
To record the measured values from the connected sensors in digital form
measuring channel scanning must be performed continuously with measured
value output according to a time-based process control. A measuring opera-
tion can be started and stopped by means of the interface, an external trigger
signal, the real-time clock, or by a specified limit value infringement. The stan-
dard cycle, settable from 1 second up, ensures an even cyclic output. If a
higher speed is required, standard sensor values can be scanned and output
at the sampling rate; however, all sensors can now use the new scan cycle;
this, if set to minimum time, obtains measured values from each channel indi-
vidually according to its own actual measuring duration.
Date and time-of-day
Each measuring operation can be accurately logged using the real-time clock
in terms either of date and time-of-day or purely by actual measuring duration.
For the purposes of starting / stopping a measuring operation, the start / stop
date and time-of-day can be programmed via the interface.
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