5. Introduction
Measuring quantities and ranges
Appropriate measuring quantities and ranges are available for all V6 sensors
with a non-linear characteristic, e.g. 10 thermocouple types, NTC and Pt100 pro-
bes, and flow transducers (rotating vanes, hot-wire thermoanemometers, Pitot
tubes). or humidity sensors there are additional function channels available for
calculating humidity variables such as dewpoint, mixture ratio, absolute humidity,
vapor pressure, and enthalpy - now on the basis of the latest formulae as per Dr.
Sonntag. Even complex chemical sensors are supported. Measured values from
other sensors can also be acquired using the voltage, current, and resistance
quantities with individual scaling in the plug itself. Existing sensors can still be
used - so long as the appropriate ALMEMO® plug is connected via its screw ter-
minals. or digital input signals, frequencies, and pulses there are adapter plugs
available with an integrated microcontroller. The new autonomous D7 sensors
already provide this wide range of features but also in the future they herald as
yet unimagined possibilities in data acquisition from both digital and analog sen-
sors and in all manner of data formats. It will even be possible to control the
measuring system itself. It is for example possible to connect an increasing ran-
ge of sensors to the ALMEMO® V7 measuring instrument and to change sensors
without needing to reset.
Function channels
Maximum, minimum, average, and differential values of certain measuring
points can be programmed as function channels and can be processed and
printed out like normal measuring points. There are also function channels
available for special measuring tasks, e.g. to determine thermal coefficient Q/
ΔT and the wet-bulb globe temperature.
Units
The units display (V6 two characters, D7 up to six characters) can be adapted
for each measuring channel in such a way that both the display and the prin-
tout always indicate the correct units, e.g. when a transmitter is connected.
Conversion between °C (Centigrade) and ° ( ahrenheit) is performed auto-
matically.
Measured value designation
To help identify sensors an alphanumeric designation is also provided (V6 10
characters, D7 up to 20 characters). This name is entered via the interface
and will appear in the printout or on the computer display.
Correction of measured values
The measured value on each measuring channel can be corrected both in
terms of zero-point and gain; this means that even sensors usually requiring in-
itial adjustment (e.g. expansion, force, pH) can be interchanged freely. Zero-
point correction and, partly at least, gain adjustment can be performed at the
touch of a button.
There is also the possibility of performing multi-point adjustment or user-defi-
ned linearization.
10 ALMEMO® 809
