Michell Instruments OptiCal, Руководство пользователя

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OptiCal User’s Manual
Michell Instruments 25
APPLICATION SOFTWARE
The Display Units and Channel 1 mA output are selected by clicking the left hand mouse
button in the relevant box. This will change the settings of both the instrument and the
virtual hygrometer window. Changing the mA outputs from 4-20 mA to 0-20 mA & vice
versa will change both Channel 1 & Channel 2 mA outputs.
The maximum and minimum values of Channel 1 and Channel 2 are –200 to +1000
respectively, therefore allowing the range of the outputs to be anywhere between these
limits. The values for Max and Min must be integer values with a difference between
them of at least 1°C/F.
If Channel 1 is to be set for %RH, gm
-3
, gkg
-1
, or ∆ (t – t
dp
), then the minimum value
of Channel 1 Min should be 0, as a negative value for these parameters is not possible.
The pressure value is used to correct gm
-3
and gkg
-1
for atmospheric pressure. By
entering the atmospheric pressure the display and Channel 1 mA output (if either gm
-3
or gkg
-1
is selected) will both be corrected accordingly.
The Alarm can be set to
OFF
or set to be active on any of the process variables i.e.
dew point, ambient temperature, temperature difference, %RH, gm
-3
or gkg
-1
as shown
above. The set point needs to be an integer value between –200 and +1000, although
negative set points are only valid for dew point and ambient temperature. If the process
variable exceeds the set point, the
Alarm
indicator on the virtual hygrometer will
illuminate and the Optics Fault/Alarm relay will change state.
To change any of the values, enter the required value and click on the return key. The
background of the text box will change to yellow to indicate that the change is taking
place. When con fi rmation has been received that the instrument has accepted the
change, the background will change back to green.
NOTE: When the
Parameter Setup
window is open, the values in the
Virtual
Hygrometer
window are frozen. The
Parameter Setup
window needs to be
closed for the software to resume normal display mode.