46 MARCH 2016 | FUEL OIL NEWS | www.fueloilnews.com
HVAC/ HYDRONICS
CLASSIFIED ADVERTISING
When using any of these instruments, care should be taken to
handle them properly. Analyzers should be vented of all samples and
be in an upright position when stored. Also, instruments should be
at room temperature when in use. Under adverse conditions, disre-
gard first CO2 test as a warm-up/ cool-down procedure.
Proper use especially hinges on the proper insertion depth of
sampling tubes. The tubes should end at roughly the center of
the pipe to trap the hottest and most highly concentrated flue gas
samples. The thermometer's bimetal is at the end of the probe
and in the case of electronic instruments; the thermocouple
is also at the end of the sending tube. One manufacturer's use
of spring clips is especially conducive to obtaining the desired
insertion depth.
When using most thermometers, most of the units found
in the manufacturer's kits have stem lengths of 5 inches. This
allows for accurate temperature readings for up to and including
a 10-inch diameter fluepipe. When taking temperature readings
on a larger pipe, a longer stem on the instrument is preferred.
Bacharach makes a thermometer with an 11-inch stem and this
longer stem will properly accommodate up to a 22-inch fluepipe.
Temperature of flue gas has always been, and still is, one of
the single most important tests we perform on heating plants.
From knowing that a 1-% CO2 change will affect temperature
25°F, we can make burner adjustments with accurate thermom-
eters very easily. So, it is very important that we use and maintain
the equipment to the best of our ability.
Finally, in this discussion about the basic use of instruments,
the calculators or slide rule charts and tables should be touched
upon. Some tables are temperature compensated at 50°F, but
others require the subtraction of ambient temperature, i.e. the
average temperature of the basement or boiler room.
Subtraction of 100°F should only be used when measured
ambient temperature is 80°F or better.
If your test is questioned, it is probably better in these days
of consumer awareness and energy auditing to be lower than
higher. A good way to confirm basement temperature is to
simply carry in your kit a regular wall thermometer, such as the
ones your company may already give away to new customers.
See ya!
l F O N
George Lanthier is the owner of Firedragon Academy,
a Massachusetts Certified School teaching both gas and oil.
Firedragon Academy has its hands-on training facility in Sturbridge,
Massachusetts at the Beckett Training Center. Firedragon is also
a publishing firm publishing George's over 60 books and manuals
on gas and oil heating and HVAC subjects. He is a CETP, NATE,
NORA, PMAA and PMEF Proctor and has been a Massachusetts
Certified Instructor since 1975. He can be reached at 608 Moose
Hill Road, Leicester, MA 01524. His phone is 508-421-3490 and his
website can be found at FiredragonEnt.com
