8. Pairing
alternate in the wireless measuring instrument display. The components have
been successfully paired.
5. Switch the wireless measuring instrument OFF again by pressing and holding
down the ON PROG key (5); the sensor module can now be withdrawn from so-
cket M0.
9. CONNECTING SENSORS
Virtually any ALMEMO
®
sensor can be connected at ALMEMO
®
input socket
M0 on the measuring instrument (1) (except D7 sensors).
However, please note, when performing long-term measuring operations under
battery power, that sensors with high current consumption may drastically
shorten the remaining operating time. To connect your own existing sensors
you simply need the appropriate ALMEMO
®
plug.
9.1 Sensors
The ALMEMO
®
Manual includes detailed descriptions of the comprehensive
range of ALMEMO
®
sensors (see Manual, Chapter 3) and instructions for
connecting your own existing sensors to ALMEMO
®
instruments (see Manual,
Chapter 4). All standard sensors with an ALMEMO
®
plug usually have the
measuring quantity, range, and units already programmed and can thus be
connected to the input socket without further adjustment. A mechanical coding
system ensures that sensors and output modules can only be connected to the
correct sockets. All ALMEMO
®
plugs incorporate two snap-lock levers; these
snap into position as soon as the plug is inserted into the socket, thus preven-
ting unintended disconnection if the cable is pulled accidentally. To withdraw
the plug these two levers must first be pressed in at the sides.
For devices with the optional seal (option W) sensors are available with spray-
coated ALMEMO
®
plugs incorporating a double sealing lip to protect the socket
unit against the effects of splashing water. For any unused sockets protective
stoppers are available.
9.2 Measuring inputs und additional channels
The ALMEMO 2790 measuring instrument has one input socket (1) to which in-
itially measuring channel M0 is assigned. However, ALMEMO
®
sensors can, if
necessary, provide up to four channels. The additional channels can be used
in particular for humidity sensors with four measurable variables (temperature /
humidity / dewpoint / mixture ratio) or for function channels.
It may be advisable to program one channel for monitoring the battery voltage
so that this value is also available in the evaluation system.(see 7.1) Each sen-
sor can if necessary be programmed with several quantities or scaling settings;
and two or three sensors, if pin assignment so allows, can be combined in a
single plug (e.g. RH / NTC, mV / V, mA / V, etc.). The additional measuring
channel numbers per connector go up in steps of 10; e.g. the first sensor has
channels M0, M10, M20, M30 maximum.
14 ALMEMO
®
2790
