MAS
page 10
MAS K05/0722
9. Operation
Pressure- and temperature conditions
The gas flow rate output of your MAS always refers to “standard” conditions of 21
°
C
(70
°
F) and 760 mm of mercury (1 atmosphere), unless you have specified
otherwise. Make sure that your MAS is always calibrated on the operating
conditions.
Accuracy
The standard accuracy of the MAS is
±
1.5% of full scale.
Overranging
If the flow rate exceeds the full scale range listed on your MAS’s front label, the
output signal and digital display (if available) will read a higher value.
Overrange conditions are indicated from the display and/or output by going to a
high level, above the full scale range. After the overrange condition has been
removed, it may take several seconds for the MAS to recover and resume normal
operation. This will not harm the instrument.
Zero and Span Adjustments
The zero and span potentiometers are accessed through marked ports on the
right side of your MAS. The analogue output is factory set and should only be
adjusted, when the zero point is drifting away more than 2% of the maximum
scale value and when you are absolutely sure that no gas is flowing.
Standard 0-5 V
DC
Output Signal
The standard 0-5 V
DC
output signal flows from Pin 3 (0-5 V
DC
Out) through the
load (1 K Ohm minimum) to Pin 7 (Power Common). The figure below is a typical
example of input power and output signal connections.
