Alpha Moisture Systems DS1200 User Manual page 16

Model DS1200-AMT-Ex
Model DS1200-AMT-Ex
8 Normal Opera
8.1 Analogue 4-20mA Mode (3-wire)
In normal opera
propor onal to the level of moisture in the gas being monitored. The moisture
reading is sampled and up dated once per second. The Model AMT-Ex has 3020
dis nct steps over the 4 to 20mA range corresponding to a resolu
8.2 Autocal
Warning Do Not power down during the AutoCal process as this
AutoCal allows the user to ensure accuracy to the laboratory calibra
the span of the transmi
periodically, every 2 to 3 months or when verifica
required.
The Model AMT-Ex is supplied with an electronic autocal, which allows the calibra
span of the transmi
located on the side of the Model AMT –Ex labelled 'W' (wet) and 'D' (dry).
Note : - The Model AMT-Ex must be connected to an indicator or some device able to
supply an accurate measurement of the mA output.
8.3 Pre-condi
To perform the autocal, the transmi
which point the display/indicator will read the ambient dewpoint or full scale (if the
ambient dewpoint level is above the range of the AMT-Ex). Expose the transmi
the known autocal moisture level and allow the transmi
technical ques
Model AMT-Ex supplier). See next steps on page 15.
14
on
on, the transmi er will produce a 4-20mA signal, which is
can lead to corrup
er and correc
er to be adjusted. The autocal is controlled by the 2 bu
oning the transmi
ons and advice on the
on of the AMTs memory.
ng for any devia on. It should be operated
on of the Model AMT-Ex is
er
er needs to be removed from the process gas at
me taken to a ain equilibrium Contact your
on of 0.005mA.
on by checking
er to a ain equilibrium. (For
on
ons
er to
2148 - Iss 6 - 10/23