UL Calibration Requirements: Equipment Ud for UL/C-UL/ULC Mark Follow-Up Services
UL defi nes minimum requirements for calibration of inspection, measuring and test equipment (IMTE) required as part of its Follow-Up Services Procedures. The requirements also include IMTE supplied by customers and ud by
UL fi eld reprentatives during inspection activities at the inspection location. Standards ud to calibrate such inspection, measuring and testing equipment are also covered by the requirements.
This document applies to all customers of UL’s product certification rvices for the U.S. and Canadian markets,
<, UL/C-UL/ULC Mark certifications. Calibration is a requirement of UL certification as noted in the United States and Canadian testing and certification rvice terms and conditions located at /contracts.
Why this requirement is important
A key element in determining compliance with UL requirements
is the validity and accuracy of inspection, measurement and
test results. Equipment ud to perform the activities must
be calibrated to provide the necessary level of confi dence in
the results of the inspections, measurements and tests being conducted. Calibration of IMTE – as well as the standards
菊花的姿态for calibration – must be traceable to the National Institute
of Standards and Technology or another national metrology institution. It is recommended that providers of calibration rvices should be accredited under ISO/IEC 17025. See page 3 of this document for calibration certifi cate requirements for calibrations performed by a non-accredited laboratory or performed in-hou by the manufacturer.REQUIREMENTS
Equipment requiring calibration
All IMTE required as part of a UL Follow-Up Services Procedure including any Appendices, Follow-Up Inspection Instructions or Standard Appendix Pages or equipment that is ud by UL fi eld reprentatives while conducting inspection activities at the factory must be calibrated.
Customers must ensure that the IMTE lected for each measurement is capable of meeting measurement tolerances specifi ed in UL Follow-Up Services Procedures or related documentation, i.e., customers must lect and u the right tool for the job.
When inspection, measuring and test equipment with low precision capability, such as tape measures, steel rules, protractors, radius gauges, etc., are ud as the fi nal means of verifying compliance with UL requirements, customers have the following options:
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Option 1
At a minimum, customers will have an appropriate accuracy statement from the manufacturer of a measuring device to certify or attest to a device’s stated precision and accuracy capabilities. This information is important in demonstrating that equipment accuracy is capable of meeting required measurement tolerances. In addition, tape measures and similar low-precision inspection, measuring and test equipment shall undergo in-rvice checks. During an in-rvice check, the measuring device is validated prior to u to ensure it is capable of achieving the required measurement accuracy. Customers must specify the criteria, frequency and methods ud to condu
ct the in-rvice checks, as well as the process for handling non-conformances.
Option 2
Customers may choo to include tape measures and similar low-precision IMTE in their calibration system. This equipment will be calibrated or validated at regularly defi ned intervals, according to requirements defi ned in this document.
Instruments and gauges that are an integral part of equipment ud in manufacturing products are not generally subject to calibration requirements, unless specifi cally identifi ed in the Follow-Up Services Procedure. Typically, the are gauges and instruments ud to monitor process characteristics, e.g., speed, pressure, etc., not product characteristics.
Frequency of calibration
All IMTE described in a UL Follow-Up Services Procedure as well as Appendices, Follow-Up Inspection Instructions or Standard Appendix Pages or ud by UL fi eld reprentatives in activities
at a manufacturing location must be calibrated at least annually for their intended function and u. If a UL Follow-Up Services Procedure specifi es more frequent calibration frequency, then that frequen
cy is to be followed.
Measurement standards
Measurement standards ud in the calibration of IMTE must also be calibrated and are to be ud for calibration purpos only.Weights and gauge blocks standards must be calibrated by a competent body – preferably by an ISO/IEC 17025 accredited calibration rvice provider – every three years or whenever
the measurement standard has been subject to some form of abu that may affect the measurement standard’s fi tness for u. Other measurement standards, e.g., voltmeters, master gauges ud to calibrate other gauges, etc., shall be calibrated by a competent body – preferably by an ISO/IEC 17025 accredited calibration rvice provider – either annually or in accordance with the equipment manufacturer’s specifi cations, or whenever the standard has been subject to some form of abu that may affect the fi tness of a standard.
Standards, including any related software, shall be protected from damage or deterioration and must be maintained according to the original equipment manufacturer’s recommendations.
Calibration identification and status
农转非All IMTE being calibrated – as well as measurement standards ud for calibrations – shall include evidence of calibration status, e.g., a label or other marking indicating the next calibration due date. If size limitations or usage environment prevents the u of a calibration label, alternate identifi cation methods are acceptable, providing that the identifi cation and calibration status can be readily determined. Each piece of calibrated IMTE must have a unique, unambiguous identifi er such as manufacturer name and model number, rial number, identifi cation number, ast number, etc.
Calibration certificates: ISO/IEC 17025 accredited calibration rvice providers
UL recommends using calibration rvice providers that are accredited to ISO/IEC 17025 through authorized signatories of an international accreditation body. See page 4 for more information on accreditation endorments. Using an accredited calibration rvice provider expedites review of calibration records during
a UL inspection visit: the calibration information that UL fi eld reprentatives need to verify is limited due to calibrations being performed in accordance with a calibration rvice provider’s accreditation requirements.
During UL inspection visits, UL fi eld reprentatives will evaluate calibration records. Each calibratio
n certifi cate from an accredited calibration rvice provider shall include at least the following information:
• Unambiguous identifi cation of the calibrated item. Some
examples are manufacturer name and model number, rial
number, identifi cation number, etc.
•Date(s) calibration was performed to determine that the IMTE has been calibrated within required frequency
•A valid accreditation body endorment for the calibration
performed. Plea refer to page 4 for a sample list of
accreditation endorments
During UL inspection visits, UL fi eld reprentatives will confi rm that the inspection, measuring and testing equipment is within the defi ned calibration period. Additionally, UL fi eld reprentatives will r
eview calibration data to verify that inspection, measuring and test equipment has been calibrated for the measurements for which it will be ud.
If the above information is unavailable or cannot be verifi ed, UL reprentatives will evaluate compliance with the requirements specifi ed for non-ISO/IEC 17025 accredited calibration rvice providers or calibrations performed in-hou.
Calibration certificates: non-ISO/IEC 17025 accredited calibration rvice providers or calibrations performed
in-hou
Certifi cates for calibrations performed by non-ISO/IEC 17025 accredited calibration rvice providers must include the following information:
1. Title, e.g., Calibration Certifi cate, Calibration Report, etc., or
equivalent
护理基础知识2. Name and address of the calibration rvice provider
3. Location where the calibration was conducted, if different
from the rvice provider address 4. Unambiguous identifi cation of the specifi c piece of IMTE
calibrated such as manufacturer name and model number, rial number, identifi cation number, etc.
5. Unique identifi er of the calibration record such as a rial
number and the capability to match it to a specifi c piece of calibrated IMTE
6. Description of the condition of the item calibrated, i.e., the
as-received condition, e.g., out of tolerance, in tolerance,
damaged, etc.
7. Date(s) calibration was performed
8. Quantitative measured value(s) of the calibration results
when out of calibration conditions are identifi ed, i.e., when stated calibration tolerances have been exceeded
9. For IMTE capable of measuring multiple parameters,
calibration records must include an attestation or statement confi rming that the equipment’s as found conditions and
calibration results encompass all parameters for which it
is being ud. Examples of this type of equipment include digital multi-meters measuring voltage, amperage and
resistance as well as 6" calipers measuring ID, OD and
depth attributes
10. The name(s), functions(s) and signature(s) or equivalent
identifi cation of person(s) authorizing the calibration
certifi cate. Note: Electronic signature/authorization is
acceptable
11. Evidence that the measurements are traceable (to national
or international standards). Note:
• There should be no alteration to the calibration data/results without evidence of appropriate authorization, e.g., names, titles, dates, nature of alteration, etc.
• When the certifi cate or report contains results of calibrations performed by subcontractors, the results shall be clearly identifi ed
For calibrations performed in-hou by customers, calibration results may be reported in a simplifi ed manner. However, any information outlined in this ction that is not included on the calibration certifi cate or report shall be readily available for review at the manufacturing location.
Out of calibration conditions
When IMTE (before any adjustments are made) is found to be outside of required calibration tolerances, i.e., OEM accuracy specifi cation, customers shall perform an analysis to determine
if the out of calibration condition could have adverly affected inspection results. Similarly, this sam
e analysis must be performed if equipment is determined to be non-operational, if it is discovered to be defective or if other conditions exist that would rai questions about the validity of previous measurements/test results.
The equipment in question must be removed from rvice by gregating or prominently labeling it. The customers shall:
• Evaluate and document the effects of the equipment on
previous inspections or tests
• Evaluate if the condition of the equipment could have
signifi cantly affected previous inspections or test results
and take corrective action, as appropriate. Customers must
take action to correct product that does not comply with UL
requirements
Corrective actions taken by customers should include a robust root cau analysis, containment actions, and long-term corrective actions to ensure that any nonconformance is not likely to recur.
Traceability
All calibrated IMTE is to be calibrated using measurement standards traceable to a national metrological institute, e.g., National Institute of Standards and Technology in the United States or an offi cially recognized national metrology institute participating in Bureau International des Poids et Measures (BIPM), either directly or through a regional group.
Note: Citation of a NIST test number, certifi cation of the calibration lab to ISO 9001, or a simple statement of traceability to NIST or other international body by the calibration rvice provider are not acceptable as evidence of traceability. The calibration certifi cate and related records must provide evidence that a calibration rvice provider utilized calibration standards that are traceable to national standards.
Measurement uncertainty
While not required, UL recommends that calibration certifi cates
or reports include the uncertainty of measurement values associated with the calibration data. Uncertainty calculations
are recommended for all calibrations. The calculations
may be performed in accordance with ISO 5725-2, Guide to
the Expression of Uncertainty in Measurement Accuracy of Measurement Methods and Results – Part 2, also known as GUM (trueness and precision), or in accordance with ANSI/NCSL Z540-2, General Requirements for Calibration Laboratories and Test Equipment.
RECORDS
Certificates and other records
如何编辑图片Customers must maintain records of calibration for at least one year. For equipment calibrated less frequently, e.g., every three years, calibration records shall be maintained at least for the current calibration cycle.
The content of the records must comply with the requirements
defi ned in this document.
Records of analysis of out-of-calibration conditions shall also be maintained. The duration of records retention should be defi ned and documented by customers. UL also recommends that customers maintain records of in-rvice checks for low-precision equipment such as tape measures.
Accreditation endorments
The following information is provided to assist customers; it is not intended to be all-inclusive.
Since calibration certifi cates from accredited laboratories that conduct work within their scope of accreditation can bear an endorment of accreditation, attention to verifying a suitable endorment with the unique identifi er is necessary. This satisfi es the need to substantiate that a certifi cate was provided by an accredited calibration laboratory.
The following are acceptable accreditor endorments:
• International Laboratory Accreditation Cooperation MRA
signatories – a full listing of ILAC MRA signatories can be
found at www.ilac/membersbycategory.html. The
category “Full Members” includes a listing of the signatories to the ILAC MRA.
• Asian Pacifi c Laboratory Accreditation Council MRA
signatories – a full listing of APLAC MRA signatories can be
found at www.aplac/membership_by_category.html.
• European Accreditation Cooperation MRA signatories – a
寒假日记500字full listing of EAC MRA signatories can be found at www.
european-accreditation/content/mla/scopes.htm.
Sample calibration certificate
The calibration certifi cate/record shown on pages 6-7 is a reprentative example that contains the required elements
defi ned previously in this document. The required elements include the following:
1. Title, e.g., Calibration Certifi cate, Calibration Report, etc., or
equivalent
2. Name and address of the calibration rvice provider
3. Location where the calibration was conducted, if different
from the rvice provider address
4. Unambiguous identifi cation of the specifi c piece of IMTE
calibrated such as manufacturer name and model number,
rial number, identifi cation number, etc.
5. Unique identifi er of the calibration record such as a rial苹果电脑截屏
number and the capability to match it to a specifi c piece of
calibrated IMTE
6. Description of the condition of the item calibrated, i.e., the
“as received” condition, e.g., out of tolerance, in tolerance,
damaged, etc.
7. Date(s) calibration was performed
8. Quantitative measured value(s) of the calibration results
when out of calibration conditions are identifi ed, i.e., when
stated calibration tolerances have been exceeded
9. For IMTE capable of measuring multiple parameters,
calibration records must include an attestation or statement confi rming that the equipment’s as-found conditions and
calibration results encompass all parameters for which it
is being ud. Examples of this type of equipment include
digital multi-meters measuring voltage, amperage and
resistance as well as 6" calipers measuring ID, OD and
depth attributes
教师退休
10. The name(s), functions(s) and signature(s) or equivalent
identifi cation of person(s) authorizing the calibration
相互批评certifi cate. Note: Electronic signature / authorization is
acceptable
11. Evidence that the measurements are traceable (to national
or international standards)
Important notes
• UL does not endor any vendors or products referenced
herein.
• For more information, plea contact your local UL Field
Reprentative.
