User guide

39
6Setupwiththedisplayandadjustmentmodule
MINITRAC 31 • Foundation Fieldbus
41782-EN-131119
Caution:
Duringtherstsetuporafteraninstrumentreset,thelinearization
stands at the preset value pair (90000 ct/s and 0.500 g/cm
3
). These
values are not suitable for your application and must be replaced by
realvalues.Deletethisvaluepairinthefollowingprocedureandcarry
outthelinearization.
Duetothemeasuringprinciple,thereisnolinearrelationshipbetween
pulserateanddensity.Hence,thisadjustment(i.e.linearization)must
be carried out in any event.
Carryoutthisadjustmentwithseveralpointstoincreasetheaccuracy
of the measurement.
Note:
Waterhasasaknowndensityvalueof1g/cm
3
. Carry out the adjust-
mentwithwater,ifpossible.
•
Prerequisites:
Radiationisswitchedon-Sourcecontainerissetto"ON"
Thetubeiscompletelylled.Possiblegasbubblesorairinclusions
caninuencethemeasurement.
The MINITRAC 31 sorts the points automatically according to their
density.
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wasdetermined,youcanacceptthevalue.
The count rate is stated in ct/s. This is the number of counts per sec-
ond, i.e. the measured radioactive radiation dose actually reaching
the sensor.