Martel Electronics 320 - Manual (Page 38)

The Model 320 does not employ any overpressure
relief bypass. The maximum overpressure for the
various sensors is given in the specifications section.
Exceeding these pressures can cause a shift in the
calibration of the unit or permanent damage to the
sensor.
OPERATION
LOOP POWER SUPPLY
The Loop Power Supply (LPS) contains eight (8) AA
Ni-Cd batteries that provide power to a DC to DC
converter. This converter boosts the battery voltage
(10.6 to 9.2) to 24 VDC
±
5%. The LPS is intended
for use as a power suppy for any two wire, 4 to 20
milliamp instrument requiring 24 VDC power.
Battery life is 6 hours nominal at 20 milliamps. Full
specifications can be found on page 51.
The LPS is designed to turn itself on and off
automatically, based on current demand. When a
series loop exists at the LPS loop power jacks calling
for .5 milliamps or greater, the LPS will automatically
36