GasSens
Gas Detection System
Section 5 - A11-10 Br2 Sensor/Transmitter
O & M Manual
Revision E, 10/15
5 - 6
FIGURE 5-2: SENSOR/TRANSMITTER CONTROLS AND TEST POINTS (ATI-096)
TRANSMITTER ZERO
The transmitter zero is adjusted with the sensor exposed to air that contains no bromine.
Generally, the easiest method of zeroing the transmitter is to make the adjustment when you know that the
area is free of bromine. The absence of bromine can be verified fairly easily by isolating the sensor from
the ambient air and observing the test point voltage (or the receiver display, if nearby). Prior to placing the
calibration adapter on the sensor, observe the DVM reading. Slide the calibration adapter onto the end of
the sensor and observe the DVM reading for the next 5 minutes. If bromine or some interfering gas is
present in the ambient air, the value on the DVM will begin to decline. If the value remains stable (± 0.02),
the sensor is at zero, and the DVM reading can be adjusted to 0.00 ± 0.01 VDC using the zero
potentiometer shown in Figure 5-2.
The transmitter can also be set to zero using "zero air" available in cylinders. Zero air cylinders
and regulators are available from ATI or from specialty gas suppliers. Connect the zero air cylinder to the
calibration adapter and adjust gas flow to 500 cc/min. When the display stabilizes near zero, adjust the
zero potentiometer until the display reads 0.00 ± 0.01 VDC.
NOTE: If using the receiver display when adjusting the transmitter zero, place the receiver in the
"Inhibit" mode as described in Section 2 of the manual. When in the inhibit mode, the
blanking around zero is disabled so that the zero can be set accurately.
