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 CHAPTER 2.
DEVELOPING A METERING PROGRAM
Section 1.
METER SELECTION
1. METER SELECTION. Selection of metering equipment consists of much more
than purchasing a meter compatible with the system to be metered. Selection
of metering equipment for electricity is greatly simplified as the operating
principles of electrical metering devices exhibit little variation compared to
fluid metering equipment. Purchasing electric metering equipment basically
requires an identification of measurements to be made, the parameters of the
system, a decision on remote metering, and selection of a meter that fulfills
these requirements. Metering of fluid systems requires additional effort.
Figure 2-1 is an example of the system information necessary to optimize a
fluid type meter selection. Figure 2-1 used in conjunction with Table 2-1 is
an example of an iterative process for proper meter selection. Another
selection method recommends the factors shown in Figure 2-2. Whatever
criteria selected, they must be tailored to the specific installation to
ensure that any problems are fully highlighted in the process. The
individuals involved in the selection process must be knowledgeable of the
sources to be monitored, the information required, and the capability of the
meters being evaluated. Another major consideration is the purpose of the
meter: control or accountability. Once the information contained in figures
2-1, 2-2, or other criteria is available, a tentative meter(s) selection can
be made. At this point , manufacturers of this type meter should be
consulted. Although most manufacturers provide extensive cooperation, their
claims should be thoroughly evaluated to insure that a particular choice is
optimum for the intended application.
1.1 Permanent and Portable Meters. In establishing an energy management
program, the use of permanent or portable meters shall be evaluated. Meter
locations must be evaluated individually to ensure accounting for all factors
pertinent to meter installation and maintenance.
1.1.1 Fluid Meters. Intrusive flowmeters, particularly differential pressure
and positive displacement types, always have some degree of pressure loss
associated with their operation. Consequently, if continuous data recording
is not required, portable insertion meters may be used for temporary
metering. If continuous metered data is required, but pressure losses are a
concern, non-intrusive meters should be considered, despite their greater
initial costs. Because most permanent meters are pipe size specific, costs
increase in proportion to pipe size. Insertion meters do not generally
increase in price as pipe size increases, and are generally more economical
for larger pipe sizes. Figure 2-3 shows a cost comparison of a permanently
installed orifice plate meter versus an insertion type meter. Typically, the
cost advantage crossover occurs between the 6- to 8-inch pipe size.
1.1.2 Electric Meters. The usual distinction between panel (permanent) and
portable electric meters is whether they are fastened securely to the facility
or capable of being hand carried. Most electric meters are made in both
2-1
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