NCWM National Conference on Weights and Measures
The National Conference on Weights and Measures issues an NTEP Certificate of Conformance following successful completion of an evaluation of a device. It indicates that the device(s) described in the Certificate is/are capable of meeting applicable requirements of the NIST Handbook 44.
A device is a weighing or measuring instrument such as a computing scale or meter indicating in volume. It also refers to major elements such as indicating elements, weighing elements and volume registers.
A device type is a model(s) of a particular measuring system, instrument, element or field standard that positively identifies the design. A specific type may vary in its measurement range, size, performance and operating characteristics as specified in the NTEP Certificate of Conformance.
This term refers to devices that are used for selling, purchasing, exchanging, custody transfer, or establishing the cost for services or hire on the basis of a measurement.
Only those devices used in trade or commercial applications and where type evaluation criteria exist, are subject to type evaluation. Non-commercial devices are not subject to type evaluation. Additionally, some states may require local type evaluation of commercial devices not evaluated by NTEP to satisfy local statutes and regulations. It is the responsibility of the manufacturer and/or distributor to ensure the device complies with all appropriate laws and regulations.
The type evaluation process is generally limited to those devices that affect the accuracy of the measurement process. Components or equipment attached to or used in conjunction with a device are required to be submitted for type evaluation only if they have or can have an effect on the accuracy of the device. Remote printers, secondary remote indicators and other periphery equipment require NTEP approval only if they perform metrological functions other than changing unit prices or calculating total price. However, such devices are subject to metrological control during field inspections.
NTEP evaluates other equipment (attached to the measuring device) that may affect the measurement process or may affect the validity of the transaction (i.e. electronic cash registers interfaced with scales and service station consoles interfaced with retail fuel dispensers).
Metrological functions are functions of a device necessary for the measurement process, that can have an impact on the final quantity determination, or price calculation for transactions, or that can affect the validity of transactions. They include the sensing of the measured or the influenced quantity, the transmission, process, storage and corrections or adjustments of measurement signals or values and the display or recording of measurement values.
The time required to initiate and complete a type evaluation varies with the type of device and any backlog that may exist in the laboratory. NTEP policy requires the NTEP laboratories to operate on a “first come, first served” basis. Once a type evaluation is started, if deficiencies are found and modifications must be made to a device, the evaluation will be discontinued. Once the corrections have been made and the device is returned to the NTEP laboratory, the device will be placed at the end of the queue; testing will resume when the device reaches its turn in the testing queue. Type evaluation testing can usually be started within 1 to 4 months of receiving the application. If no deficiencies are found during the initial evaluation, a type evaluation may be completed in approximately 1 to 3 months.
Applicants may indicate their lab preference. An effort will be made to satisfy the applicants' request. However, because of the workload of the requested laboratory, another laboratory may be designated. The NTEP Administrator reserves the right to select the laboratory.
Many manufacturers produce both weighing or measuring systems and separate indicating and weighing/load-receiving elements to be "mixed and matched" with other compatible equipment. Some manufacturers produce only one part of the complete system. The practice of "mixing and matching" equipment is permitted and recognized in the type evaluation process by evaluating separate main elements and issuing type evaluation certificates for the separate main elements. It is unrealistic and cost prohibitive to conduct type evaluations on every combination of indicating and weighing or measuring elements, hence, the "mixing and matching" of equipment is permitted. It is the responsibility of the manufacturers and distributors of "mix and match" equipment, to ensure that the application works properly and is installed and set-up to be consistent with state and/or local weights and measures requirements and the manufacturer's instructions.
If the device fails to meet the requirements of the NTEP evaluation, the applicant will receive a written deficiency report from the laboratory stating the applicable regulations that the device failed to meet along with information supporting this conclusion. The applicant will have 90 days from the receipt of the deficiency report to correct the deficiencies and resubmit the device to the laboratory. If the device fails three evaluations, it will then enter the excessive failure process. The applicant will be notified by NCWM and will have 90 days to submit proof of corrective action to NCWM. If corrective action is considered acceptable, one final evaluation will be conducted. If corrective action is deemed to be insufficient, or if the device fails to meet all requirements during this fourth evaluation, the project will be closed.
The devices are being manufactured or remanufactured for commercial application under and NTEP Certificate of Conformance. This means that the Certificate is in force and all fees have been paid.
An inactive Certificate of Conformance is a Certificate which was previously active, but the devices are no longer being manufactured for commercial applications subject to local regulations or laws; however, devices already manufactured, installed or in inventory, but not yet sold, may be used, sold, repaired and resold under inactive Certificates of Conformance.
The U.S. and Canada have signed a Mutual Recognition Agreement (MRA) for certain weighing devices. Each party issues their own document upon successful completion of testing.
Many states require that a device have an NTEP Certificate of Conformance prior to installation in a commercial application. Sometimes a state may permit a device to be installed for the purposes of conducting a type evaluation or if a completed type evaluation does exist from another location, pending the publication of the Certificate of Conformance.