Sensor Purchases-Remember the Big Picture

Ray Peacock

When you choose a sensor for a project, you're also establishing a relationship with an expert organization and its key people. Your vendor will help you and your organization get the most from its sensor. If you buy from a catalog or base your purchase decision solely on price, you'll miss the added benefits a sensor partner brings to your operations.

A Source of Expertise
Keep in mind, the sensor supplier is an expert in the sensing area in which you are involved and a valuable technical resource, regardless of your own level of experience. This is particularly true these days. Many companies have cut maintenance, R&D, and technical-support staff, so in-house sensor specialists are often a rare commodity.

Cross training welders and electricians may increase the number of people in your company who can follow a wiring diagram, but it doesn't cultivate staff capable of evaluating technical needs and instrument specifications. Experts today often reside in the vendors' operations. You need to tap that expertise. A purchase order can provide access to that resource.

Why do you need support? Here are just a few reasons.

  • When setting up and using sensors, you may need help determining if they are tuned properly for the process you are measuring and/or controlling. You may need information that you cannot find in the manuals. Expert help usually lies with the vendor.

  • When integrating the sensor into your measurement or control system, how do you make initial and regular verifications? The vendor has done that more than once (if you picked correctly).

  • Who provides operator and service training? A capable vendor has applications and training specialists who will help, often at surprisingly low cost.

  • Will your vendor support repairs/replacements? One that cares about its customers always will.

  • Who can help you with the next job that has similar requirements. A vendor that you already know and whose expertise you have tapped before to solve a problem.

Picking a Partner
You can use the vetting process of potential suppliers to evaluate their technical expertise. If their products are similar and support features equal, the rapport you develop with one or more vendors will help you decide whom you would work with best.

In addition, when you review sensor specifications submitted by each vendor, pay careful attention to exceptions they might include. Ask the vendors to review their bids and detail the reasons for exceptions. A competent vendor will not hesitate to point out relevant issues you may have missed. These points are usually spelled out in the supplier's exceptions to a bid specification. Be alert for the signals; the suppliers are usually the real experts.

You may also want to visit the vendor's key people to gauge the company's expertise first-hand and check key aspects of its manufacturing practices and product testing. This is a good way to get to know some of their key support and technical staff, which can prove invaluable in the long run.

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