Measurement Equipment Buying Checklist: FARO Laser Trackers, Digital Dial Indicators, Keysight Oscilloscopes, and More

I'm the guy who signs off on purchase orders for a metrology service shop. Nine years in, 14 mistakes—maybe 13, I'd have to check our Q2 2022 report—roughly $36,000 in wasted budget. I kept a record because my boss wanted to know why our tool budget kept disappearing. This is the checklist I wish someone had handed me in 2017.

If you're here because you searched “FARO CMM machine price,” or you have a used laser tracker FARO unit on a pallet, or you're trying to figure out how to use Keysight oscilloscope the right way — stop and read this first. The tool itself is rarely the problem. The problem is the 20 minutes before buying, and the settings you don't check after it arrives.

Use this checklist when you're about to buy, rent, or switch to any measurement instrument: a digital dial indicator, a portable CMM arm, a FARO laser tracker, HPLC columns, an oscilloscope. It takes about 30 minutes to run through. That's 30 minutes that can save you from a $5,000 error.

Step 1: Write the requirement down before you search for prices

Before you google anything, answer three questions:

1. What exactly are you measuring? A bore diameter? A flatness? A waveform edge? Column separation?
2. What tolerance do you actually need? Not the project manager's “nice to have” — the one that affects fit and function.
3. How will you prove the tool is working? Calibration certificate, gauge block, certified reference sample?

“I need an accurate measurement” is not an answer. “I need to verify a 12.00 mm bore with ±0.005 mm uncertainty, and I'll use a calibrated ring gauge” is an answer. The difference determines whether you need a digital dial indicator or a $50,000 FARO laser tracker—and saves you from buying the wrong thing.

Step 2: Don't start with “FARO CMM machine price”

“FARO CMM machine price” is the first search I see from new buyers. It makes sense. You want budget numbers. But quoting a measurement system without calibration, software license, probe kit, operator training, freight, and an extended service contract is like quoting a car without dealer fees. The sticker price isn't the total cost.

If you ask three vendors for a “FARO CMM machine price,” you'll get three different answers, and they won't include the same things. Ask for a full quotation with line items, not a single number. Then ask, “What does this exclude?” The answer tells you more than the number.

Small-customer note: I've placed $200 orders with vendors who answered questions for an hour, and I've placed $20,000 orders with a different shop that made me feel stupid. The $200 order was the test. Small doesn't mean unimportant—it means potential. Good suppliers treat small and large the same because they know what a large order looks like later.

Step 3: Choose a laser tracker FARO model only if you actually have a moving problem

This is gonna sound obvious, but I almost bought a FARO laser tracker because everyone in a trade show booth praised it. The honest question was: “Do I need to measure a large object in free space, or can I bring the object to a coordinate measuring machine?”

A laser tracker FARO model earns its price when you need measurements on a 3-meter weldment, on an assembly line, or on a turbine blade in the field. If everything you measure fits on a bench, a digital dial indicator and a calibrated fixture are faster and less expensive.

The most common mistake is buying portability you don't need. A portable CMM arm is not “better” than a fixed CMM—it's different. I'm not going to say stationary CMMs are obsolete, because they aren't. But before you sign anything: if you're relying on a laser tracker, ask the vendor whether the accuracy claim follows ISO 10360-10, and ask for the test report. A one-line “laser accuracy ±20 µm” without a standard is just marketing.

Step 4: Check a digital dial indicator before you trust its display

A digital dial indicator is one of the most common—and most reassuring—pieces of metrology equipment. The big number on the screen makes you believe it's accurate. The fine print says “resolution 0.0005 inch.” Resolution is not accuracy. If the indicator hasn't been checked with a gauge block, that last digit is just decoration.

My rule: before any run, put the indicator against certified gauge blocks near your measurement nominal. Zero it, check the block, remove it, check again. The repeatability tells you more than the display. So glad I did this before a critical QC batch last year—one gauge block was reading 0.0004 inch high, and it would have turned eight good parts into “scrap.”

Also, check the contact point. A tiny burr on the stylus can add a few tenths to every reading. I caught that after a $3,200 rework. The indicator was fine. The stylus had a nick. The boring step nobody does before touching the screen is sometimes the difference between a trustworthy reading and another headache.

Step 5: How to use Keysight oscilloscope controls without trusting Auto-Scale

If you searched “how to use Keysight oscilloscope” and just want to see a waveform, you'll probably press Auto-Scale. That's fine for a smoke check. It's not fine for a measurement you're going to write down.

Three settings that are easy to skip but matter:

1. Probe attenuation. If the probe is 10× but the scope is set to 1×, your amplitude reading is wrong. The scope doesn't know what you intend.
2. Trigger mode. On Normal, the scope updates only when the trigger condition is met. On Auto, it free-runs and shows a waveform that may be untriggered. If you don't know which one is on, you can misjudge signal stability.
3. Memory depth and sample rate. A long timebase with low memory undersamples a fast edge. Even a clean line on the screen can hide a glitch if the scope didn't capture enough points.

I wasn't careful with the third one once. I reported a clean digital pulse, and a colleague saw the raw data and found missing samples. It wasn't a Keysight flaw; it was lab-user error. So glad I checked the sample math before publishing that report—one click away from putting a clean pulse on the record that didn't exist.

Step 6: Don't assume a new HPLC column is a drop-in replacement

HPLC columns are not mechanical instruments, but they are part of a measurement system. The column's dimensions, particle size, and stationary phase chemistry determine pressure, retention, and resolution. The same phase name from the same manufacturer still behaves differently when the particle size changes.

I once ordered an apparently identical replacement for a 4.6 × 150 mm HPLC column, but the original was 5 µm and I bought 3 µm. The separation looked better—then the backpressure sent the lab pump into a fault state. The service call was $2,000, I want to say, though I might be misremembering the exact number. The delay was three days and the lesson was permanent.

The “most people skip” trap: comparing model names instead of specifications. Read the particle size, pore size, and column hardware compatibility before you hit order.

Step 7: Rent or demo before you commit

For big-ticket items like a FARO laser tracker or a portable CMM arm, rent one for a week. A rental is expensive, but it's cheaper than the wrong purchase. Test it on your actual part, not on the polished demo pyramid they set up in your conference room.

I once compared two portable arms. The data sheets looked identical. My gut said the cheaper one felt flimsy. Every spreadsheet said the specs were the same. I pushed for a side-by-side on our own heavy weldment. The cheaper one lost zero repeatability after the third re-measure. The numbers didn't lie—they just didn't include the bearing change the vendor had made. I went with my gut, and my gut was right.

Step 8: The two-minute pre-PO check

Before approving any purchase order, I look for these:

• Does the quote list each item on its own line? “Measurement system complete” is not a line item.
• Does the calibration certificate show a date, a certificate number, and traceability? NIST-traceable or ISO 10360-2 needs an attached report.
• What is the lead time? If it's longer than the project timeline, no price matters.
• Is operator training included? If not, add the cost and schedule now.
• Can you get a re-calibration cost in writing? That's the recurring price nobody quotes until you ask.

“Calibrated to ISO 10360-2” without a report is not a calibration. It's a hope.

I once ordered the right portable arm but the wrong mounting plate for the stand. $1,200 wasted plus a one-week delay. Now I physically match the thread and thread size before sending the PO. Sounds dumb. It was dumb.

Final notes: small orders and gut checks

If you're in a one-person lab, don't apologize for asking detailed questions on a $200 digital dial indicator. The vendor who doesn't take you seriously at $200 won't become more helpful at $20,000. I know because I've lived it.

And when your data and your gut disagree, don't ignore either one. Write down what the data says, what your gut says, and what experiment would settle it. That's the checklist you'll actually use.