GasSens
Gas Detection System
Section 2 - A14 Receiver Module
O & M Manual
A14-RK, 8/06
2 - 6
Range Selection
Display range selection is made using binary numbers to represent the full scale operating
range for the receiver. Table 2-2 provides the proper switch settings for the ranges available on
each receiver. Range selection is made using switches C1-C4. The 4-20 mA output signal is
proportional to the selected range.
Ranges marked with 'LSD Fixed' indicate that the least significant digit on the display always
reads zero.
TABLE 2-2
DISPLAY
RANGE
SWITCH
SETTINGS
DISPLAY
RANGE
SWITCH
SETTINGS
0-1.00
0000
0-50
1000
0-2.00
0001
0-100
1001
0-3.00
0010
0-200
1010
0-4.0
0011
0-500
1011
0-5.0
0100
0-1000
1100
0-10.0
0101
0-1000 LSD Fixed
1101
0-20.0
0110
0-2000 LSD Fixed
1110
0-25.0
0111
0-5000 LSD Fixed
1111
Relay Configuration
Receivers contain 3 SPDT relays that actuate based on gas concentration. Relays can be set
to actuate when the gas concentration either goes above or falls below the setpoint. Most gas
leak detection applications require alarms to activate above a specific setpoint, but alarms for
oxygen deficiency require relay actuation below the setpoints. Switch A1 selects relay operation
either above or below setpoints and applies to all relays.
Each relay can be assigned to either the warning or alarm setpoint. As shown in Figure 2-4,
switches D3, D6, and C6 configure each relay . When warning is selected, the relay will activate
when the warning lamp on the front panel lights. When alarm is selected, the relay will activate
with the alarm lamp on the front panel.
Relays may be either Latching or Non-latching. A latching relay activates when gas
concentration exceeds the setpoint, but will only deactivate when the
A/R
button is pressed, and
then only if the gas concentration has fallen below the setpoint. A non-latching relay will
automatically deactivate when the gas concentration falls below the setpoint without
A/R
button
being pressed. Selection of the latch/non-latch function uses switches D4, D7, and C7.
