83 Ill. Adm. Code 501.10
Definitions and Incorporations by Reference
Section 501.10 Definitions and Incorporations by
Reference
a) Definitions
"Act" means the Public
Utilities Act [220 ILCS 5].
"AGA" means the American
Gas Association.
"Alternative Gas
Supplier" has the same meaning as in Section 19-105 of the Act.
"ANSI" means the
American National Standards Institute.
"Answer Time" means a
measurement from the point the customer dialed the last digit of the natural
gas public utility's or alternative gas supplier's telephone number and a
natural gas public utility or alternative gas supplier representative or
automated system is ready to render assistance or accept information to process
calls.
"Auxiliary Equipment"
means an integral device attached directly or remotely to a gas meter. The
function of auxiliary equipment is to adjust gas meter usage measurements to
account for changes in gas temperature or pressure.
"Bell Prover" means a
cylindrical metal tank open at the top and nearly filled with liquid, in which
a smaller calibrated cylindrical tank called the bell, open at the bottom and
having a dome-shaped top, can be raised or lowered. As the operator raises
(negative pressure) or lowers (positive pressure) the bell, the bell will
displace a known volume of air.
"British Thermal Unit" or
"BTU" means the quantity of heat required to raise the temperature of
one pound of water one degree Fahrenheit from 58.5°F to 59.5°F under a standard
pressure of 30 inches of mercury at 32°F, or 1054.804 Joules.
"Complaint" means an
objection
made to a
natural gas public utility
or alternative gas supplier
, by a customer or another
entity, as to its charges, facilities or service. Complaints include a customer
or other entity identifying and asking a
natural gas public utility or
alternative gas supplier
to address or resolve a
problem or concern and shall not include contacts that are limited to inquiry
or seeking information.
"Compressibility" means
a gas volume correction factor calculated by using the parameters of natural
gas composition, flowing gas temperature, and flowing gas pressure. The
compressibility correction factor compensates for the deviation of gases from
the ideal gas laws with increased pressure and with variations in temperature
and gas composition. Compressibility is not to be confused with "supercompressibility",
which is also defined in this Section.
"Coriolis Meter" means a
gas meter that infers mass flow rate by measuring tube displacement resulting
from the Coriolis effect.
"Corrector" means a
device that corrects uncorrected gas meter volume according to the gas laws
(Boyle's Law, Charles' Law, and Real Gas Law).
"Commission" means the
Illinois Commerce Commission.
"Commission Referee
Test" means the accuracy test of any gas meter made in the presence of one
or more members of Commission Staff.
"Cubic Foot" means the
unit of volume for purposes of measurement at a base temperature of 60°F at a
base pressure of 14.73 pounds per square inch absolute.
"Custody Transfer Meter"
means the meter, auxiliary equipment and tertiary equipment a utility uses to
measure a customer's gas usage.
"Diaphragm Meter" means
a positive displacement, bellows-type gas meter that alternately fills and
empties compartments of known volume and totals the number of times the cycle
occurs to determine the volume of gas passing through the meter.
"Defective Meter" means
a meter whose condition is impairing service to a customer or a meter that has
failed the requirements of Sections 501.170, 501.180, 501.190, 501.200,
501.210, 501.220 or 501.230.
"Flow Computer" means a
device that electronically converts signals from a gas measurement system to a
useful form such as flow rate.
"Fixed Factor" means the
use of a gas pressure regulator to control gas pressure within an allowable
pressure band over the required flow rate range considering the variation of
inlet pressures and results in the application of a pressure correction factor
applied via an arithmetic application or special index to a customer's measured
usage.
"Master Bell" means a
primary bell prover used as a reference standard for target proof correlations
and bell prover interface recertification.
"Measurement Error"
means an error in the calculation of a customer's gas usage due to the inaccuracy
or improper setup of a utility's meter or other equipment whose function
directly or indirectly affects the utility's measurement of a customer's gas
usage.
"Meter Accuracy" means
the overall performance of a particular meter in relationship to a known
reference or portable standard.
"Meter Soaking Room"
means a room maintained at the same atmospheric conditions as the meter proving
room. The purpose of a meter soaking room is to store and acclimatize meters
prior to testing to ensure meter testing accuracy that is not affected by
temperature variations.
"Multi-path Ultrasonic
Meter" means a device that derives gas flow rate by measuring the transit
times of high-frequency sound pulses. Sound pulses transit between pairs of
transducers located on or in the gas pipe.
"Natural Gas Supplier"
means an alternative gas supplier or any other natural gas supplier providing
the natural gas commodity to a customer under a gas utility tariff or rider.
"Orifice Meter" means an
inferential meter that consists of an orifice plate perpendicular to the gas
flow in a pipe. When gas flows across the orifice, it creates a pressure
differential. Transmitters and transducers measure the pressure differential,
static pressure, and other variables to determine the flow rate. The flow rate
is proportional to the square root of the differential pressure across the
orifice plate.
"Portable Standards"
means instruments that utilities use in the field or the meter shop to test the
accuracy of auxiliary and tertiary equipment, transmitters, and other equipment
associated with correcting a meter's output.
"Proving Room" means a
temperature-controlled room where the utility uses equipment to determine the
accuracy of meters.
"Rated Capacity" or
"Badged Capacity" means the hourly gas throughput of a meter as
defined by the meter manufacturer.
"Reference Standards"
means instruments that utilities use only for verifying the accuracy of
portable standards, and whose accuracy is traceable back to the national
standard maintained by the National Institute of Standards and Technology (NIST)
or its successor.
"Rotary Meter" means a
positive displacement meter that alternately fills and empties rotating
compartments of known size and totals the number of times the cycle occurs to
determine the volume of gas passing through the meter.
"Service Applicant"
means a person who applies for residential or non-residential utility service
for a location where the utility has not yet installed the meter.
"Small Commercial Customer"
has the same meaning as in Section 19-105 of the Act.
"Sonic Nozzle Automatic
Prover" means a device containing a parallel bank of sonic flow nozzles
that it uses to determine actual gas volume passed through a gas meter in order
to determine the gas meter's accuracy.
"Sub-metering" means the
placement of a meter downstream of a custody transfer meter.
"Supercompressibility"
means a value used in some flow equations for differential pressures (for
example, orifice metering). In general, the supercompressibility factor is
equal to the square root of the quotient of gas compressibility at base
conditions divided by the gas compressibility at flowing conditions.
Supercompressibility is not to be confused with "compressibility".
"Tertiary Equipment"
means a device that electronically converts signals from a gas measurement
system (meter or auxiliary equipment or both) to a useful form such as flow
rate (for example, flow computers).
"Therm" means a unit of
measurement representing a quantity of heat equivalent to 100,000 BTUs and
expresses the energy content of natural gas.
"Transducer" means a
sensing element capable of transforming values of physical properties such as
pressure or temperature into equivalent electrical signals.
"Transmitter" means a
device designed to enhance the transmission of information from a transducer to
a flow computer by the addition of an electrical circuit that converts the
transducer output to a standard signal in analog, digital or frequency form.
"Turbine Meter" means an
inferential meter that measures gas flow by counting the revolutions of a rotor
with blades, which turn in proportion to the gas flow velocity.
b) Incorporations
by Reference. The following materials are incorporated by reference as of the
date stated and include no later editions or amendments.
American Gas Association, 400
North Capitol Street, NW, Washington DC 20001
AGA Report No. 3, Orifice Metering
of Natural Gas − Part 2: Specification and Installation Requirements,
XQ0002 (April 2000)
AGA Report No. 7, Measurement of
Natural Gas by Turbine Meter, XQ0601 (February 2006)
AGA Report No. 9, Measurement of
Gas by Multipath Ultrasonic Meters, XQ0701 (April 1, 2007)
AGA Report No. 11, Measurement of
Natural Gas by Coriolis Meter, XQ1301 (February 1, 2013)
AGA Gas Measurement Manuals – Part
15: Electronic Corrector, XQ9901 (May 1999)
AGA Gas Measurement Manuals – Part
8: Electronic Flow Computers and Transducers, Revised (1988), XQ8805 (May
1988)
American National Standards
Institute and American Society for Quality (American National Standards
Institute, 25 West 43
rd
Street, 4
th
Floor, New York, New
York 10036)
Sampling Procedures and Tables for
Inspection by Attributes, ANSI/ASQ Z1.4-2008 (January 1, 2008)
American National Standards
Institute and American Gas Association (American National Standards Institute,
25 West 43
rd
Street, 4
th
Floor, New York, New York 10036)
Diaphragm-Type Gas Displacement
Meters (Under 500 Cubic Feet Per Hour Capacity), ANSI B109.1-2000, AGA XQ0008
(June 2000)
Diaphragm-Type Gas Displacement
Meters (500 Cubic Feet Per Hour Capacity and Over), ANSI B109.2-2000, AGA
XQ0009 (June 2000)
Rotary-Type Gas Displacement
Meters, ANSI B109.3-2000, AGA XQ0010 (June 2000)