Ahlborn ALMEMO 2590-2 Operating Instructions Manual page 9

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 re-
sistance ranges with individual scaling in the connector. Existing sensors can
also be used - so long as the appropriate ALMEMO
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
ment 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/∆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 (Centigrade) and °F
(Fahrenheit) 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. Sensors with multi-point calibration can also be connected;
(see Manual Section 6.3.13).
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 scaling
values can be calculated automatically by setting to zero and entering the nomi-
nal setpoint or via the scaling menu.
Limit values and alarm
Per measuring channel two limit values can be set (1 maximum and 1 mini-
®
connector is connected
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measuring instru-
ALMEMO ® 2590
Functions
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