User guide

31
6Setupwiththedisplayandadjustmentmodule
MINITRAC 31 • Foundation Fieldbus
41782-EN-131119
Thismenuitemenablesadaptationofthesensortotherequestedap-
plication.Youcanchoosebetweenthefollowingapplications:"Level",
"Density", "Limit level", "X-ray alarm" or "Real value correction".
Thenaturalradiationonearthinuencestheaccuracyofthemeas-
urement.
With this menu item the natural background radiation can be faded
out.
For this purpose, the MINITRAC 31 measures the natural background
radiationandsetsthepulseratetozero.
Inthefuture,thepulseratefromthisbackgroundradiationwillbe
automatically deducted from the total pulse rate. This means: only
thecomponentofthepulserateoriginatingfromthesourcewillbe
displayed.
The source container must be closed for this setting.
In this menu item you can select the units of the process value and
the temperature.
In this menu item you can enter the measuring range (min. and max.
process value) of the sensor.
Thesesettingsinuencethecurrentoutputofthesensor.
Enterinthemenuwindow"Max. process value" the max. level (full),
for example in "m". This corresponds to an output current of 20 mA.
Enterinthemenuwindow"Min. process value" the min. level (empty),
for example in "m". This corresponds to an output current of 4 mA.
In this menu item you can carry out the adjustment of the sensor.
Duetothemeasuringprinciple,thereisnolinearrelationshipbetween
pulse rate and level. Hence, this adjustment (i.e. linearisation) must in
any case be carried out.
Note:
Ifyoucannotllthevesselwiththeoriginalmedium,itisalsopossible
tocarryouttheadjustmentwithwater.
Prerequisites:
Radiationisswitchedon-Sourcecontainerissetto"ON"
Thevesseliseithercompletelylled(100%)orcompletelyemptied
(0 %).
Dependingonthefactifthevesselislledoremptied,youcancar-
riedoutrstthefullortheemptyadjustment.TheMINITRAC31sorts
the points automatically according to their level.
Select "Show table"todisplayandeditthelinearizationpoints.
Select "Linearization - New"toentertherstpoint.
Select "Determine count rate"toentertherstpoint.
The determination of the actual count rate lasts 2 minutes. After the
count rate has been determined, you can accept the value (ct/s).
Enternowthecorrespondinglevel(m).
Setup - Background
radiation
Setup - Units
Setup - Adjustment
Setup - Linearization