PressureMAT User Guide
Revision 8
Page 24/48
2.2.
Using the System*
1.
Using the instructions from the previous section 1.2.3, set the appropriate high and low alarm
pressure settings for each channel. The unit is supplied with the low alarm set at -7 psi (- 0.5
bar) and with the high alarm set at 30 psi (2 bar). These are the set-points that will trigger an
alarm condition. High and low pressure settings are entered on the key pad and if the process
pressure goes below the low setting or above the high setting, the system will go into alarm
state. The alarm function includes:
a.
An audible tone for 30 seconds,
b.
If present, a dry contact relay associated with that channel will switch (i.e., if wired as
normally CLOSED, it will OPEN; if wired as normally OPEN, it will CLOSE)
When an alarm condition goes away, all indicators automatically go back to normal (unless the
optional alarm latching function is turned on which requires the STOP button to be pressed to
clear the alarms). If the alarm settings are set to 0.00, then no alarm conditions are monitored,
however, if a sensor is disconnected, an alarm will still occur.
2.
If a pressure sensor is not connected or is disconnected during operation of the system, the
pressure reading will drift and eventually go to a value greater than 75psi/5.17 bar and an alarm
condition will occur if the high alarm set-point is surpassed or in psi when the value goes
above the hard-coded limit of 75. . The time until the high alarm occurs may vary and this
feature should not be used to control a process due to the time variance (and a 20mA signal
will be transmitted from the analog output and/or relays will switch, depending on model).
3.
The HOME screen will display pressure from the sensors that are connected.
* See Section 3 for information on the flow meter input function and Section 4 for analog input
function.
