Quality Magazine

Other Dimensions: Calibrate Your Own Tools?

August 1, 2004
Answer your calibration question with some basic questions.

Many manufacturers who use outside calibration sources often ask whether it is cost effective to outsource this task when they review the annual cost of using a contractor. It is tempting to think that costs can be lowered by bringing calibration in house, and for some, they may be correct in doing so. Unfortunately, many manufacturers do not look at the subject objectively and get themselves and their company in trouble. In other cases, manufacturers know that bringing calibration in house will increase costs, but it serves other ends and so that decision is not about saving money. The answers to whether tool calibration should be outsourced or done in house are easy to come by; asking the correct questions is the difficult part. To discover the correct questions, it's best to turn to journalism for guidance, even if many journalists don't follow the basic rules of their profession these days. The questions every news report should answer are: Who? What? Why? Where? When? A manufacturer should ask these questions when considering whether to bring calibration in house. These basic questions, when applied to the calibration scenario would become: u Why bring calibration in house? u Who will do the calibration? u Where will calibration be done? u What will be the cost of in-house calibration? u When can calibration work be done? The purpose behind the questions is to ensure that a manufacturer look at the complete in-house calibration picture rather than just what he perceives as the best parts of his decision. In fact, if a good case already exists for moving calibration in house, the answers to these questions will help make the case better. And, answering these questions will help avoid costly or embarrassing surprises later. Some of the best gage and instrument calibration laboratories in the world are in-house facilities. Many surpass independent laboratories in efficiency and technical competence. Developing a competent in-house calibration facility is not about trade secrets, magic and mystery. It's about knowing what is being done during calibration. Not all facilities are this good, unfortunately. Many hours are wasted, and expenses incurred, by the gaging industry battling over a few millionths of an inch or parts of a micron with manufacturers who do their own calibration. There are skills and knowledge required to correctly calibrate gages and measuring tools. There is also a certain level of precision required in the equipment used. I have heard many manufacturers who are considering in-house calibration comment, "We don't have to be as good as you people [contract gage calibration facilities]," as they start compromising on equipment. If a manufacturer rejects a gage a qualified supplier has made and that has gone through a proven independent laboratory, the manufacturer does have to be as good as the contract calibration facility. I believe most, if not all gage makers would agree with this premise, with the rare exception of when the gage in question is off by a mile. The principles of metrology don't change just because a manufacturer decides to bring calibration in house. The same rules that govern a properly accredited outside lab must be followed by a manufacturer or the resulting calibration won't be worth the time it took to obtain. Before making the decision to bring tool calibration in house, there are legal considerations to take into account. If a manufacturer is well known and considered to have buckets of cash, and therefore, open to class action suits when things go wrong with its product, legal counsel may have very strong views on the plan to bring calibration in house. Make sure a lawyer is aware of what could happen if mistakes are made on the calibration of a gage or tool used to check a product that could become the subject of litigation. I don't want to cause fear, but if a lawyer has opinions on the subject you can rest assured the insurance company will too, especially when it comes to liability clauses in a policy. It might not be all bad. The insurance company may be thrilled about a manufacturer who wants to put calibration under his direct control and becomes accredited by a recognizable outside agency. In my next few columns I will provide more detail on the questions I have posed for consideration in making the decision whether to bring tool calibration in house. And, I will give you ways to arrive at answers that pertain to your particular situation.