3
INTRODUCTION and OVERVIEW
The SenTech Environmental System IR-SNIF-MCD refrigerant monitor provides an early
warning of developing refrigerant leaks. The unit samples ambient air and measures the
amount of halogen based refrigerant gas in the air sample. When the proportion of refrigerant
present exceeds a trip point, the system goes into alarm mode. Should the system assess the
presence of refrigerant as a leak, using SenTech’s “LEAK WAIT” algorithm, the user is notified.
By discovering a leak shortly after it starts, the potential loss can be reduced to ounces of
refrigerant, saving money and helping protect the environment.
Functional Description
The refrigerant monitor is composed of four major functional blocks: Pneumatics, Infrared
Bench, Control Electronics and Power Supply. Refer to figure 1 for an overall block diagram.
The pneumatics pulls sample air or reference air from up to 250 feet and pumps the air
through a filter, to a pressure sensor, through the infrared bench and out the exhaust port of
the monitor. The infrared bench provides an infrared source and measures the presence of
refrigerant based on measured changes in the infrared light. The control electronics switches
the pneumatic valves from one area to reference air and on to the next area, measures and
stores the information from the infrared bench, provides a human machine interface for
programming and provides analog, digital and relay outputs to interface with building systems
and alarms.
IR
B
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n
c
h
Press. Switch
D
ia
p
h
ra
g
m
P
u
m
p
Relays
Terminal Board
Control Electronics
LOW MAIN HIGH
Valves
Area 1
Reference Air
P
o
w
e
r
S
u
p
p
ly
V
a
lv
e
D
ri
v
e
r
B
o
a
rd
TB3
Terminal Board
TB6 (opt.)
HORN
Area 5
Area 6
Area 2
Area 4
Area 7
Area 8
Area 3
Exhaust
Figure 1 Overall Block Diagram
Summary of Contents for IR-SNIF-MC-1
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