Find the short list

Labs are everywhere… so begin by narrowing your options to a short list of labs handling the kind of test you want and preferably nearby. Most testing can be done by mail, but all things being equal, wouldn't you prefer to deal face to face with a company providing a service that could make or break your company or product?

I recommend: Use ThomasNet to get a list of labs in your state, with a link to a detailed profile and contact information for each lab. You can also search for all labs within a given radius from your ZIP code.

Check quality standards

In the lab world, "quality" is first measured by the conditions of the test, not the lab. There are standard quality-control procedures for almost every imaginable type of test, and for proper calibration of the instruments used in that test. Make sure your lab follows the important ones for your test type. (You can learn which quality standards apply for the test you need by consulting your industry association or by learning which standards were followed in your competitors' tests.)

I recommend: The American Society for Testing and Materials (ASTM) has a search engine which enables you to find a lab based on the quality standards the labs follow; just type in the standard name (such as ISO 9000) to find and purchase detailed PDFs explaining the standard.

Determine certification

Ask the lab about its certifications or accreditations – those vary by state. While quality standards apply to given tests or procedures, certification and accreditation guarantee that a lab knows what it's doing on a given type of testing, such as commercial products testing.

I recommend: The National Voluntary Laboratory Accreditation Program (NVLAP) offers a searchable directory of accredited laboratories. The ThomasNet directory lets you narrow search results to those labs carrying a specific certification.