User manual

H35.0.02.6C-09 Operating Manual GMH 3250 page 9 of 14
8 Notes to Special Functions
8.1 Display Resolution (’Resolution’)
Standard setting: ’Auto’, i.e. the device automatically switches over to the optimum resolution between 1° and 0.1°.
If temperatures to be measured are near the switching threashold, a fixed resolution may be better, e.g. for easy
recording.
In such a case please select the optimum resolution manually.
8.2 Zero Displacement (’Offset’)
A zero displacement can be carried out for each of the two channels CH1 or CH2.
temperature displayed = temperature measured - offset
Standard setting: ’off’ = 0.0°, i.e. no zero displacement will be carried out. The zero displacement is mainly used to
compensate for sensor deviations. Unless ’off’ is set, this value will be displayed shortly after the device is switched
on; during operation it will be identified by means of the offset arrow in the display.
8.3 Display Correction Factor (’Corr’)
This factor is applied to both sensor channels.
temperature displayed [°C] = temperature measured [°C] * Corr
or temperature displayed [°F] = (temperature measured [°F]-32°F) * Corr + 32°F
Standard setting: ’off’ =1.000
This factor is used to compensate for losses of transfer in case of surface measurements, occurring if the object to
be measured is extremely hot but will be cooled by lower ambient temperatures. The same can be true for sensors
with a large mass. Unless ’off’ is set, this value will be displayed shortly after the device is switched on; during opera-
tion it will be identified by means of the Corr-arrow in the display.
8.4 Tare Function
The tare function is used to set the DIF-display to zero, which is especially important when monitoring temperature
differences. If the tare key is pressed for more than 2 seconds DIF = CH1-CH2 will be restored. This function as well
as the DIF-display can only be used if two sensors are connected. If the tare function is activated, this will be shown
by the tare arrow in the display.
8.5 Base Address (’Adr.’)
Using the interface converter GRS3105 it is possible to connect several instruments to a single interface. As a pre-
condition the base addresses of all devices must not be identical. In case several devices will be connected via one
interface make sure to configurate the base addresses accordingly. Channel 1 will be addressed by the base ad-
dress set, channels 2 and 3 will have the following addresses.
(Example: base address 21 - channel 1 = 21, channel 2 = 22, channel 3 = 23)
8.6 Alarm
3 alarm settings are available: off (off), on with horn sound (on), on - no horn sound (no.So)
You can choose the channel to be monitored by the alarm function:
CH 1: alarm monitoring of channel 1 CH 2: alarm monitoring of channel 2
CH 1.2: alarm monitoring of channels 1 and 2 dif: alarm monitoring of difference channel
If the alarm function (on, no.So) has been activated, an audible alarm signal will be given with the following cases:
values have fallen below/exceeded the lower/upper alarm limits in the channel to be monitored
FE 9 or FE11 at the channel to be monitored
low battery
FE 7: In case of a system error the horn will be sounded regardless of the alarm setting (even if alarm = off)
If one or more alarm settings have been fulfilled the "alarm" arrow will be shown in the display; in case of access via
the interface the ’PRIO’-Flag will appear.
8.7 Real Time Clock:
The real time clock is required to put logger data in a time order. If necessary please check the setting:
Setting via keys (p.r.t. configuration of the device): time (minutes . accurate), date, year.
Setting via interface: use suitable software (seconds - accurate) e.g. GMH3050-software.
The clock setting menu will be started automatically when the device is switched on again after a battery change.