Retrotec DM-2 - Manual (Page 40)

Page 40 of 72
©Retrotec Inc. 2012
8 Use the Gauge with a calibrated fan for air leakage testing
The gauge can be used for testing either on its own, or connected to a specialized, calibrated fan.
Before it can be used for testing, it is important to know how to connect it properly.
Before beginning a test, it is absolutely critical to enable and select the proper Device and Range in
order to obtain the correct results. The Device set on the gauge must match the Device in use for the
test and the Range set on the gauge must match the Range Ring and Plate installed on the Device.
Refer to section 3 for instructions on how to enable and select the proper Device, and select the proper
Range.
8.1 Making the Connections
The gauge can be used with a Retrotec calibrated fan and other similar devices produced by other
manufacturers. The Retrotec Umbilical cable includes all necessary tubes and cable connections. The
pressure tubes in the Umbilical cable are color-coded. The pressure and hardware connection ports
are also clearly labeled on the top of the gauge.
8.1.1 Pressure port connections
Retrotec has a specially designed connection port that makes a perfect seal and grips the tube well, but
releases without tearing the tubing after multiple uses. This exclusive connector was designed by
Retrotec to make contact with the both tube internally and externally with a shallow taper. The tube
ends should be clean and not stretched in order to make a proper connection. If the pressure tube is
damaged, simply slice a short piece of tube off the end to ensure a clean fit. Tubing can crack in cold
weather, but it can be warmed in hot water before being handled. Be careful to dry all water from the
tubing prior to connecting since water in the tube is a major source of measurement error.

Green port, “Input B (+)”

- Higher pressure on this port than “Ref B” makes “PrB” read positive.

Yellow port, “Ref B (-) (fan)”

- Higher pressure on this port than “Input B” makes “PrB” read negative.

Red port, “Ref A (-)”

- A higher pressure on this port than “Input A” makes “PrA” read negative.

Blue port, “Input A (+)”

- A higher pressure on this port than “Ref A” makes “PrA” read positive.