Functions of the ALMEMO 5690-2M
5.1.1 Sensor programming
The measuring channels are programmed, completely and automatically, by
the ALMEMO
®
connectors. However, the user can easily supplement or mod-
ify this programming via the keypad or via the interface.
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 connector. Existing sensors
can also be used - so long as the appropriate ALMEMO
®
connector is con-
nected via its screw terminals. For digital input signals, frequencies, and
pulses, adapter connectors are available with an integrated microcontroller. It
is thus possible to connect virtually any sensor to any ALMEMO
®
measuring
instrument and to change sensors without the need for any extra settings.
Function channels
Maximum, minimum, average, and differential values from certain measuring
points can be programmed as function channels, also internal 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 the
temperature coefficient Q/
D
T and wet bulb globe temperature.
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 and °F is performed
automatically.
Measured value designation
Each sensor is identified by means of a 10-character alphanumeric name. It is
entered via the keypad or the interface and appears in the display, in the print-
out, or on the computer screen.
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.
Scaling
The corrected measured value on each measuring channel can also be further
scaled in terms of zero-point and gain - using the base value and factor. The
decimal point position can be set by means of the exponent function. The scal-
ing values can be calculated automatically by setting to zero and entering the
ALMEMO
®
5690-2M
13