General Tools and Instruments RLD400 - Manual (Page 3)

WHY LOOK FOR REFRIGERANT LEAKS?
There are three reasons to detect and repair leaks of refrigerant gases from
stationary and mobile air conditioners, refrigeration systems and heat pumps:
1. Leaks allow air and moisture to enter an A/C system or chiller. Moisture can
react with refrigerant to form corrosive acids and sludge that can damage a
compressor, plug up orifice tubes, and/or eat pinholes in evaporators and
condensers.
2. Refrigerant is expensive. It may seem cheaper to keep recharging your
system with refrigerant than fix a leak—but it isn’t in the long run. And A/C
systems and chillers that aren’t fully charged won’t cool efficiently and thus
waste money (electricity-powered systems) or fuel (vehicle systems).
3. Most refrigerants deplete the ozone layer that blocks the Sun's harmful
ultraviolet radiation. In the U.S., the Clean Air Act of 1990 and later
amendments require owners or operators of refrigeration and air-
conditioning equipment with refrigerant charges greater than 50 pounds to
repair leaks within 30 days when those leaks result in the loss of more than
15% (comfort cooling) or 35% (commercial cooling) of the charge over a
12-month period.
The RLD400’s proprietary sensor and detection technology are the keys to its excellent
performance and durability. Compared to products of decades past with “heated
sensors”, the RLD400 warms its sensor to a much lower temperature. The reduction in
heat reduces the instrument’s power consumption and improves sensor stability while
extending the life of the sensor and maintaining its electrochemical function.
Test data indicate no decline in the sensor’s performance after thousands of hours of
operation. Sensor life is specified at more than ten years of normal use. In addition,
because the instrument and sensor comply with SAE Standards J2791 and J2913 and
the European Standard EN14624, the sensor will not be damaged by overexposure to
refrigerant gas or by contamination by water. To comply with SAE J2791, the RLD400
also had to demonstrate its sensitivity to 15 different chemicals and pass two “garage
durability” tests, one requiring it to survive three drops from 4 ft. onto concrete.
HOW IT WORKS
A small mechanical pump inside the RLD400 draws a sample of air through the tip of
the instrument’s 17-in. long probe into a proprietary sensor 1-1/2 inches downstream. A
proportional halogen detector in the sensor determines whether any refrigerant gas is in
the sample. If any gas is detected, the sensor and other circuits measure the amount of
refrigerant and convert the value to an electrical signal.
If no leak is detected, no signal is produced and the display remains off (dark). When a
leak is detected, the signal is amplified, digitized, and displayed on the front panel as a
large, bright red number from 1 to 9 corresponding to the size of the leak (1 for the
smallest leaks, 9 for the largest).
3