5. Introduction
5.1.1 Sensor programming
The measuring channels are programmed, completely and automatically, via
the ALMEMO
®
plugs. However, this programming can be supplemented or
modified via the keypad or via the interface as and when required for measur-
ing purposes.
Measuring ranges
Appropriate measuring ranges are available for all sensors with a non-linear
characteristic, e.g. 10 thermocouple types, NTC and Pt100 probes, infrared
sensors, and flow transducers (rotating vanes, thermoanemometers, Pitot
tubes). For humidity sensors additional function channels are available for cal-
culating humidity variables such as dew point, mixture ratio, vapor pressure,
and enthalpy. Even complex chemical sensors are supported. Measured val-
ues from other sensors can also be acquired using the voltage, current, and
resistance ranges with individual scaling in the plug itself. Existing sensors can
also be used - so long as the appropriate ALMEMO
®
plug is connected via its
screw terminals. For digital input signals, frequencies, and pulses, adapter
plugs are available with an integrated microcontroller. It is thus possible to con-
nect virtually any sensor to any ALMEMO
®
measuring instrument and to
change sensors without needing to reset.
Function channels
Maximum, minimum, average, and differential values from particular measur-
ing points can be programmed as function channels, also internal channels,
and can be processed and printed out like normal measuring points.
Units
The 2-character units display can be adapted for each measuring channel so
that both the display and the printout always indicate the correct units, e.g.
when a transmitter is connected. Conversion between °C (Centigrade) and °F
(Fahrenheit) is performed automatically.
Measured value designation
Each sensor is identified by means of a 10-character alphanumeric name.
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
initial adjustment (e.g. expansion, force, pH) can be freely interchanged. Zero-
point correction and, partly at least, gain adjustment can be performed at the
touch of a button. Sensors with multi-point calibration can also be connected.
(see Manual, 6.3.13)
Scaling
The corrected measured value on each measuring channel can also be further
scaled in terms of zero-point and gain - by means of the base value and factor.
The decimal point position can be set by means of the ´
EXPONENT
´ function.
10 ALMEMO 2470
