Test Equipment Acceptance Checklist: 5 Steps Before You Sign the Receipt

I'm a quality compliance manager at an instrumentation company. I review every instrument before it reaches customers—roughly 200 units a year. In 2024, I rejected 8% of first deliveries due to calibration drift or documentation gaps. The vendors hate that number, but the customers like it.

This checklist is for anyone taking delivery of test equipment—new, rented, or freshly returned from calibration. It's five steps, and it'll take you about an hour the first time. Maybe 30 minutes once you get the rhythm. The goal is simple: catch the issues that won't show up on the spec sheet.

Why I Started Using a Checklist (and Why You Should Too)

It took me 3 years and roughly 600 inspections to understand that acceptance testing isn't about the equipment—it's about the process around the equipment. I only believed that after getting burned twice. Once, we accepted a battery tester that looked fine, passed its self-test, and then produced readings 12% off from the reference unit when it mattered. Another time, a rented power supply arrived with a calibration certificate that expired the same week. Nobody noticed until an audit flagged it.

The question isn't whether your vendor is trustworthy. It's whether someone verified the things that can go wrong in transit, in storage, or during setup.

Step 1: Review the Paperwork—Calibration, Traceability, and Rental Terms

Start with the documents. Not because I don't trust vendors, but because documentation is where the small problems hide.

For any ametek electronic test equipment rental or a new purchase, check three things:

• Calibration certificate issue date and due date. I've seen certificates expire the same week the equipment arrived. In Q1 2024, 6% of incoming rental units at our facility had less than 30 days of calibration validity left.
• Traceability chain. The certificate should show calibration against standards traceable to a national metrology institute (NIST in the US, or the equivalent in your region). If it just says "calibrated" without the traceability chain, that's a red flag.
• Rental agreement terms. If you're renting, verify whether calibration is included in the rental period or billed separately. Communication failures here have caused more budget headaches than equipment failures in my experience.

Honestly, I'm not sure why some rental houses are better than others at keeping calibration records current. My best guess is it comes down to how their database is set up. Regardless—check the dates yourself. Thirty seconds of reading prevents a month of compliance headaches.

Step 2: Power-On and Reference Test—Especially for Battery Test Instruments

Next, power the unit up and run a basic functionality check. This is where ametek battery test instruments need particular attention.

Here's my standard routine:

1. Run the unit's built-in self-test (if it has one). Note any error codes and verify they clear.
2. Measure a known reference source. For battery testers, use a reference cell or a calibrated power supply with a known output. Compare the reading to the reference.
3. Test the load function. Battery test instruments often include load testing—set the load to a known value and confirm the current draw matches within the specified tolerance.

The surprise wasn't the accuracy of the instruments themselves. It was how often the cables and connectors caused measurement drift. Loose connections, worn Kelvin clips—these created errors that the instrument itself couldn't detect. We upgraded our test leads to low-resistance types in 2022 (cost: about $300 per station) and saw measurement consistency improve noticeably.

If the instrument has been dropped or shipped, pay extra attention to the connection terminals. That's where impact damage shows up first.

Step 3: Verify Communication Setup—Encoder Profinet

This step is the one most people skip. It's also the one that costs the most when skipped.

If you're setting up an encoder Profinet device, don't assume that because the encoder is the right model, the communication will just work. Profinet is a bit particular. Here's what I run through:

1. Set the device name. Profinet identifies devices by name, not just IP address. If the name doesn't match what's configured in your PLC (programmable logic controller), the device won't connect. This is the #1 cause of "my Profinet encoder won't communicate" issues I've seen.
2. Check IP assignment via DHCP or DCP. Make sure the encoder obtained an IP address on the expected subnet. If it's on a different subnet, you'll get intermittent communication failures that are maddening to debug.
3. Verify cycle time expectations. Encoders send position data cyclically. If your PLC expects a 1ms update and the encoder is configured for 5ms, you won't see the error until you need fast response—usually during a critical move.

They warned me about Profinet configuration issues during training. I didn't listen until we had a servo axis that would randomly fault. It took a week to discover that the encoder device name had been changed by a previous programmer (ugh). The fix took 10 seconds.

Side note: I've never fully understood why some engineering teams treat network configuration as an afterthought. The encoder hardware is usually fine. The network settings are 90% of the problem.

Step 4: Validate Accuracy with Known Samples—MR176 Moisture Meter

For moisture measurement, I use a similar approach: test against a known reference. The MR176 moisture meter is a solid instrument—but like any moisture meter, its readings depend on how it's used.

Here's my validation process:

1. Test on samples with known moisture content. Keep 2–3 samples with known moisture levels (determined by a reference method like oven drying). Run the MR176 on each and compare.
2. Test on the same sample at different points. Moisture distribution isn't uniform. If you're testing a material that should have reasonably consistent moisture, readings that vary wildly between adjacent points might indicate an issue—or might just mean the material is inhomogeneous. That's a normal physical variation, not an instrument malfunction.
3. Verify the settings. Most moisture meters have settings for material type. The MR176 should be configured for the material class you're testing. It sounds obvious, but I've seen measurements taken with the wrong material setting (not that I've done it myself—well, once I did).

Part of me wants to just trust the instrument's display and move on. Another part remembers the $2,400 batch of material we rejected in 2023 because it came in at 15% moisture when we'd specified 11%. The vendor's meter said 11%. Ours said 15%. We tested both against an oven-drying reference and found the vendor's meter had drifted. The $2,400 was their cost for a replacement batch, but the delay was ours. I compromise: I trust our instruments only after they've passed quarterly validation against reference samples.

Step 5: Thermal Accuracy Spot-Check (Topdon vs FLIR)

Thermal cameras are the equipment I'm most frequently asked about. Specifically: Topdon vs FLIR thermal camera—which should we buy?

I'm not going to declare a winner, because the right answer depends on your measurement tolerance and your budget. But here's the check I run on any thermal camera, regardless of brand:

1. Verify temperature accuracy against a known source. Use a blackbody calibrator or, at minimum, a surface with a known temperature measured by a contact probe. Point the camera at it and compare. Pay attention to the accuracy spec: most cameras claim something like ±2°C or ±2%. Verify that's true for your unit.
2. Check emissivity settings. A camera set to the wrong emissivity will give incorrect readings on shiny or reflective surfaces. This isn't a camera defect—it's a setup issue. But it's the most common cause of "our thermal camera reads wrong" complaints I hear. FLIR's and Topdon's interfaces handle emissivity differently, so if you're switching brands, expect a learning curve.
3. Check spot size ratio. Every thermal camera has a distance-to-spot ratio. If you're measuring a small target from too far away, you'll average in background temperatures and get a skewed reading. This trips up more engineers than I'd expect.

Between you and me, I've seen both Topdon and FLIR units perform well in our incoming checks. I've also seen both fail accuracy validation. The brand mattered less than whether someone actually took the time to verify calibration before relying on the readings. Look, no thermal camera—at any price point—is immune to the laws of emissivity and distance.

Common Mistakes to Avoid

After reviewing 600+ instruments, these are the mistakes I see most often:

• Skipping the communication test. If you don't verify Profinet setup at acceptance, the problem surfaces on the production line, not in the receiving area. And it's always harder to troubleshoot there.
• Trusting the calibration sticker. A calibration sticker tells you a date, not a condition. If a unit was dropped in transit, the calibration might be invalid even if the sticker is current. Our protocol requires a physical impact check for all inbound units (added in 2022, after a dropped thermal camera shipped to a customer with a cracked lens that wasn't visible from the outside).
• Not logging rental calibration dates. If you're using ametek electronic test equipment rental services, enter the calibration expiry date into your tracking system the day the equipment arrives. I've seen audits where rental units were in use with expired calibration for weeks simply because nobody logged the due date.
• Assuming "factory calibrated" means "accurate now." Factory calibration is a baseline, not a guarantee.

Bottom Line

The five steps—paperwork, power-on reference tests, communication setup, moisture validation, and thermal spot-checks—take about 60 minutes for a full instrument. Thirty if you know what you're looking for. Five minutes of verification beats five days of correction, and I've got the process variance data to back that up: our first-pass rejection rate for incoming equipment dropped from 12% in 2023 to 4% in 2025 after we standardized this checklist and made it a requirement rather than a suggestion.

If you have a question about a specific instrument or protocol—or if you've found a better way to verify moisture meters or thermal accuracy—I'd genuinely like to hear it. I've been doing this long enough to know that no one person has the perfect checklist.