Procedure for Purchasing and Supplier Evaluation (20180101) Page 1 of 5

Procedure for

Purchasing and Supplier Evaluation

1. Introduction

This is the metrology laboratory procedure for purchase, storage, and evaluation of supplies and 

services. Obtaining products or services from organizations registered to ISO 9001 or accredited 

to ISO/IEC 17025 is required where possible; however, this is no guarantee of acceptable 

quality. The laboratory inspects and evaluates products or services and identifies any unique 

storage requirements when products are received or returned. 

2. Purpose

It is imperative that supplies and services obtained by the laboratory reflect the expected quality 

of service and that they do not adversely contribute to the quality of measurement results.

3. Responsibility and Authority

3.1. The Technical Manager is responsible for ensuring that suitable specifications are used 

to purchase supplies and services.

3.2. The Quality Manager is responsible for ensuring that products and services meet 

designated specifications and are evaluated once received.

4. Operations

4.1. The laboratory will use national or international specifications for standards as 

appropriate and where available and inspect the standards upon receipt to determine that 

standards meet specifications. Examples of standards include:

4.1.1. Mass standards: OIML R 111 or ASTM E 617;

4.1.2. Mass field standards: NIST Handbook 105-1, 105-8;

4.1.3. Volumetric field standards: NIST Handbook 105-2, 105-3, 105-4, 105-7; 

4.1.4. Timing Devices: NIST Handbook 105-5; 

4.1.5. Thermometers: ASTM E 1 or NIST Handbook 105-6; and

4.1.6. Proving rings or Load Cells: ASTM E 74.

4.2. In addition to specifications, and if specifications are not available, the following criteria 

will be used in purchase considerations as applicable:

4.2.1. Accreditation status of the laboratory as from an ILAC-signatory (International 

Laboratory Accreditation Cooperation) Accreditation Body;

4.2.2. Accuracy, stability, contribution to measurement uncertainty (quality factor);

4.2.3. Familiarity with the product, word of mouth experience from other laboratories 

(quality factor);

4.2.4. Prior relationship with supplier, supplier’s reputation, and commitment to 

customer satisfaction;
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4.2.5. Cost and turn-around time; and

4.2.6. Availability of product, parts, or services.

4.3. Communicating requirements

The laboratory communicates requirements to providers of products and services 

requirements listed in Sections 4.1 and 4.2 and in addition, the following requirements if/as 

applicable:

4.3.1. Specific products or services to be provided;

4.3.2. Acceptance criteria;

4.3.3. Competency requirements (including personnel qualifications); and 

4.3.4. Any activities that would be performed at the provider’s facility (uncommon).

4.4. Maintenance of records

4.4.1. The laboratory will maintain purchase and warranty records and maintain 

performance history files. In situations where the quality of product or services are 

not adequate for the intended purpose, the laboratory will investigate the issue prior 

to additional purchases. See Form 3 for Evaluation records that will be maintained; 

4.5. List of acceptable suppliers

The laboratory will maintain a list of acceptable suppliers for laboratory standards, 

equipment, supplies, and services where the quality of such products or services may affect 

the quality of the measurements. Each supplier will be evaluated initially and prior to use 

thereafter according to criteria in section 4.2. See Form 4 for acceptable List that will be 

maintained.

4.6. Examples of purchases affecting quality of measurement results

4.6.1. Laboratory supplies affecting measurement quality

• Chemicals

• Wipes

• Weight handling equipment - gloves, forceps, filter paper

• Meniscus reading tools, magnifiers

4.6.2. Standards

• Weights

• Volumetric

• Thermometers

• Barometers

• Hygrometers

• Tapes

4.6.3. Equipment
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• Balances

• Water purification system

4.6.4. Services

• Calibration of standards

• Balance repair and/or maintenance

4.7. Inspection prior to use

All products and services are inspected or validated prior to use.
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Form 3. Supplier Evaluation

Supplier Evaluation 

Date:

Supplier:

Supplier products:

Evaluation Questions:

Applicable specification Yes No

Title of applicable specification:

Supplier registration/accreditation:

Accuracy, stability, uncertainty evaluation:

Familiarity with product, word of mouth experience from other laboratories:

Prior relationship, supplier reputation, commitment:

Availability of products, parts, service:

Other comments regarding supplier:

Evaluation upon Receipt: (Acceptable?)

Signature of responsible staff:
Procedure for Purchasing and Supplier Evaluation (20180101) Page 5 of 5

Form 4. List of Acceptable Suppliers

Supplier (Address, Contact 

Info, Website) Product(s)

Accreditation 

Status (AB, Date) Acceptance Date

Latest 

Evaluation 

Date