Buying Faro Laser Trackers and CMM Arms: An Admin Buyer's FAQ

When I took over purchasing in 2020, my instinct was to keep costs down. That approach worked for office supplies, and it failed for measurement equipment. Now I process orders for everything from an 87V multimeter to a Faro laser tracker with the same first question: what is this tool actually being asked to do?

The question matters when I review a Faro CMM arm quote, and it matters when a facility manager asks me how to read Sensus water meter data for a monthly report. The hardware changes. The purchase logic does not.

This FAQ is for the person who signs purchase orders but does not live in the metrology lab. I wrote it from the buyer side, not from a technical manual.

What is the difference between a Faro laser tracker and a Faro CMM arm?

A Faro laser tracker is the big-part system. An operator moves a reflector around the object, and the tracker follows it and records points in space. That is useful when the part is the size of a car or an aircraft section, because you cannot put the part on a bench and inspect it with a handheld probe.

A Faro CMM arm is the articulated arm you bring to the workpiece. It is a contact tool. You touch the probe to the surface and the arm measures where you are. It works well for machined parts and smaller assemblies that need a high-accuracy check at the point of production.

My simple explanation is: arm for things you can reach across, tracker for things you have to walk around. An applications engineer could say it better, but until that conversation happens, this gets the budget discussion moving.

Why do Faro quotes look higher than other options I see?

Because the Faro quote usually covers more than the hardware. In my experience it includes software, local support, installation training, calibration certificates, and technical documentation that the quality department will want when an auditor asks questions. Cheaper systems can be fine for some jobs, but they often require extra purchases to do the same work.

I learned to compare the full package rather than the headline price. If two vendors offer the same measurement capability, the difference may come down to how they respond when you need help. That is hard to see in a quote, but you can test it before you buy.

The most expensive measuring instrument is the one that gives you a confident-looking number that is wrong.

That phrase is on a sticky note near my computer. It came from a day when I was trying to explain to finance why we had to stop production because of a measurement problem that a proper pre-purchase review should have caught.

Do I need to pay for Faro calibration and a service plan?

Only if you plan to believe the numbers.

I skipped a scheduled calibration once because the system had been used less than expected. It was fine for a while. Then a customer audit found that the calibration certificate had expired by three weeks. Every part we measured during that window had to be reviewed. The extra inspection and expedited calibration cost several times what the service plan would have cost. The worst part was explaining it to the customer.

Whatever service option you choose, put the next calibration date on a shared calendar. An expired certificate is a preventable problem. Prevention costs less than the conversation after the audit.

Is a portable CMM arm less accurate than a fixed CMM?

That was true for some older generation equipment, but it is not a simple rule today. A fixed coordinate measuring machine has the advantage of a controlled environment and a stable base. If you need very tight tolerances in a temperature-controlled room, and the part can be brought to the machine, that may still be the right tool.

A Faro CMM arm has a different advantage: it goes to the part. It can measure something on a shop floor, inside a machine tool, or on a large assembly that cannot fit in a measuring lab. Published accuracy for a portable arm is not automatically worse than a lab machine; it depends on the application.

The better question is where the measurement needs to happen. If you keep buying instruments that never leave the lab, a portable system may be the wrong purchase even if it costs less.

When an engineer requests a specific model like an 87V multimeter, should I try to save money?

Do not ignore the model number. Ask what feature makes that model necessary. An 87V multimeter is not just a voltage tester. It has specific safety ratings and measurement functions that protect whoever uses it. If a cheaper meter lacks the same rating, it is not a comparable product. If it has the rating, then you have a real price conversation.

The same idea shows up in weighing systems. A warehouse scale for rough inventory weight does not need the same approvals as a scale used for trade. But someone has to ask the question before money moves.

Even a simple request like 'how to read Sensus water meter' has a specification underneath it: the display may be in gallons, cubic feet, or a pulse output for an automated system. The reading is only useful if you know which unit you are looking at. Same principle as the multimeter spec, just with different hardware.

Being an admin buyer does not mean accepting every request. It means asking the why question early, before the purchase order.

What hidden costs should I ask about before buying a Faro laser tracker?

Ask these on the first call, not after the quote:

• Calibration before delivery and annual recalibration after that
• Software licenses, and whether there is an annual subscription
• Training for the people who will operate it
• Accessories that might be sold separately, like reflectors or stands
• Shipping, rigging, and duties if it is coming from another country

None of those should stop the purchase. They should be part of the calculation. If you compare five-year cost instead of first-year price, the right choice gets easier.

Can a third-party lab handle the calibration, or do I have to use the OEM?

For many instruments, a third-party lab can be a good choice. The important thing is to check the lab's certification before you need it.

Ask for a sample calibration certificate. See whether it identifies the exact instrument model and includes the measurement uncertainty. Ask who is liable if the instrument is out of tolerance and whether they will cover the cost of parts you measured while it was drifting. That last question separates a serious lab from a paperwork mill.

I have gone with a more expensive service because it answered those questions clearly and a cheaper one did not. The numbers said one thing; my gut said another. When the gap is small and the risk of being wrong is large, I go with the safer paperwork.

What is the most important question to ask before requesting any Faro quote?

Ask the person who needs the equipment to finish this sentence: 'We need to measure [specific feature] on [part] to [tolerance].'

If they can finish it, the vendor can recommend the right system, and you can compare proposals against the same requirement. If they cannot finish it, then every quote you receive is a guess. The best way to avoid an expensive mistake is to delay the purchase long enough to define the job.

I would rather be the buyer who asks one more question than the buyer who has to explain why we bought the wrong tool. That is the prevention over cure part of this job.