BILL OWENS DEPARTMENT OF LABOR AND EMPLOYMENT Governor Division of Oil and Public Safety – LP-Gas Inspection Program RICK GRICE th633 17 Street, Suite 500, Denver CO 80202 Executive Director Phone 303/318-8533– Fax 303/318-8488 RICHARD O. PIPER E-mail firstname.lastname@example.org – Web http://ops.cdle.state.co.us Division Director
REQUIREMENTS FOR CALIBRATING, ADJUSTING & SEALING
LP-GAS METERS IN COLORADO
1. The tolerances established by N.I.S.T. (National Institute of Standards and Technology) for propane (LP-Gas)
Normal (fast) test Repeatability
(1) Acceptance tolerance 0.6% (1) Tests at same flow rate 0.4%
(2) Maintenance tolerance 1.0%
Special (slow) test Determining which tolerance to apply
(1) Acceptance tolerance 1.0% (1) Apply acceptance tolerance to new meters that have
never been calibrated and sealed by the OPS. (2) Maintenance tolerance 1.0%
(2) Apply acceptance tolerance to existing meters that Automatic Temperature Compensator (Tolerance have been repaired or adjusted within the past 30 days. between compensator engaged and disengaged) (3) Apply maintenance tolerance to existing meters that (1) Mechanical ATC 1.0% were not repaired or adjusted within the past 30 days. (2) Electronic ATC 0.5%
2. Any meter whose initial calibration is outside the acceptable tolerance as established by N.I.S.T. (National
Institute of Standards and Technology) must be adjusted to as close to zero as possible. Any meter that
cannot be adjusted to the N.I.S.T. tolerance on the negative side will be immediately placed out of service. Any
meter that cannot be adjusted to the N.I.S.T. tolerance on the positive side will be placed out of service only at
the meter owner’s request.
3. Only employees of companies authorized by the Division of Oil and Public Safety (the OPS) may adjust and seal
LPG truck and retail meters in Colorado.
4. Only employees who have individually been authorized by the OPS may adjust and seal LPG truck and retail
meters in Colorado.
5. Meter owners/operators may not adjust and seal their own meters. Only a third-party may adjust and seal
6. Only N.I.S.T. Handbook 105-4-compliant volumetric provers may be used to calibrate LPG meters. Use a prover
large enough to accommodate the maximum flow rate of the meter. In general, use at least a 100-gallon prover
to calibrate a truck meter, and at least a 25-gallon prover to calibrate a retail meter.
7. All provers must be calibrated by a NIST certified state metrology laboratory. All provers must be re-calibrated
every 24 months, or earlier if the prover has sustained damage or if there is reason to question its accuracy. [In
Colorado, the state metrology laboratory is at the CO. Dept. of Agriculture, Measurement Standards Section,
3125 Wyandot St. Denver, CO 80211-3859, phone 303-477-4220. Certification from another state’s metrology
laboratory is also acceptable.]
8. Proper calibration of an LPG meter includes the following:
a. Fast test as found, with compensator engaged. [If there is no compensator, omit this test.] If within
b. Fast test with compensator disengaged. If within tolerance, then
c. Slow test with compensator disengaged.
9. Each company authorized to calibrate, adjust and seal LPG meters shall apply to renew its authorization every
12 months, using the form provided by the OPS.
10. Each individual authorized to calibrate, adjust and seal LPG meters shall apply to renew his/her authorization
every 12 months, using the form provided by the OPS.
11. No company or individual whose authorization to calibrate, adjust and seal LPG meters has lapsed or been
rescinded by the OPS may seal LPG meters.
12. Seals shall be lead and wire seals at least 3/8” in diameter.
13. The seal press shall identify the company and the identifying number of the individual technician who calibrated
and sealed the meter.
14. Each company authorized to calibrate, adjust and seal LPG meters in Colorado shall provide to the OPS a
legible copy of its identifying company seal.
15. The OPS may rescind a company’s or an individual’s authorization to adjust and seal LPG meters if any of the
a. Follow-up inspections by the OPS indicate multiple instances when the actual calibration is outside NIST
b. Follow-up inspections by the OPS indicate unusual circumstances, such as all adjustments showing a
c. Information on a company’s or individual’s application is found to be false.
16. Each company whose employees calibrate, adjust and seal LPG meters will provide to the OPS reports of new
or remanufactured meters placed in service, repaired meters returned to service, and in-service meters
calibrated and sealed. These reports shall be on the forms required by the OPS and shall be submitted to the
OPS within seven (7) days of the activity date.
17. An individual authorized by the OPS to seal LPG meters shall return to his/her employer the company seal at
such time as his employment with that company ceases.
18. Allowing private companies to adjust and seal LP-Gas meters does not in any way compromise or replace the
state’s calibration program. OPS inspectors will continue to calibrate, adjust, and seal all Colorado LP-Gas
meters as scheduled, regardless of whether a private company has already performed this function. Only OPS
inspectors may use the official OPS lead seal. Private technicians will use their company’s identifying seal.
I have read and understood the foregoing requirements, and I agree to abide by them.
Signed: Date: Print or type name: Title: