Portland Natural Gas Transmission System

Second Revised Volume No. 1

Effective Date: 09/01/2006, Docket: RP06-449-000, Status: Effective

Original Sheet No. 322 Original Sheet No. 322 : Effective

GENERAL TERMS AND CONDITIONS (Continued)

6.5 Care Required. All installations of measuring equipment applying

to or affecting deliveries of Gas shall be made in such manner as to permit an

accurate determination of the quantity of Gas delivered and ready verification

of the accuracy of measurement. Reasonable care shall be exercised by both

parties in the installation, maintenance and operation of pressure regulating

equipment so as to prevent any inaccuracy in the determination of the quantity

of Gas delivered under any Gas Transportation Contract.

6.6 Calibration and Test of Meters. The accuracy of Transporter's

measuring equipment shall be verified by Transporter at reasonable intervals,

and if requested, in the presence of representatives of Shipper, but

Transporter shall not be required to verify the accuracy of such equipment

more frequently than once in any thirty (30) Day period. In the event either

party shall notify the other that it desires a special test of any measuring

equipment the parties shall cooperate to secure a prompt verification of the

accuracy of such equipment. The expense of any such special test, if called

for, shall be borne by Shipper if the measuring equipment tested is found not

to be in error in the amount which would cause an aggregate flow rate

calculation greater than two percent (2%).

If, upon test, any measuring equipment, including recording

calorimeters, is found to be in error, and causing a flow rate calculation

error of not more than two percent (2%), previous recording of such equipment

shall be considered accurate in computing deliveries of Gas, but such

equipment shall be adjusted to record accurately.

If, upon test, any measuring equipment shall be found to be inaccurate

by an amount exceeding two percent (2%), at a recording corresponding to the

average hourly rate of flow for the period since the last preceding test, then

any previous recordings of such equipment shall be corrected to zero error for

any period which is known definitely, but in case the period is not known or

agreed upon, such correction shall be for a period of the latter of one-half

of the time elapsed since the date of last test, or a period of sixteen (16)

Days.

6.7 Correction of Metering Errors -- Failure of Meters. In the event

a meter is out of service, or registering inaccurately, the volume of Gas

delivered shall be determined:

(a) by using the registration of any check meter or meters, if

installed and accurately registering, provided that the check meter is of a

type commonly used in the industry and has been tested and with eased on the

same frequency as the meter; or, in the absence of (a);