Measurement Equipment Buying Checklist: SICK Encoders, Thermal Cameras, Scales, and More

I took over purchasing at our plant in 2020, and somehow never gave it back. I'm not the engineer who specifies tolerance or sensing range. I'm the office administrator who deals with purchase orders, delivery dates, invoices, and the occasional item that doesn't work because we ordered the wrong version. I manage about 100 orders a year across 8 vendors, and I report to operations as much as finance.

Quick scope note: SICK is the industrial sensor manufacturer, not the adjective for feeling unwell. If you landed here with a search like sick real thermometer high fever, that's not what this guide covers. SICK doesn't make fever thermometers. This article is about industrial measurement and sensing equipment.

If you're buying a SICK IO-Link encoder, a weighing scale, a thermal camera, or even a Starrett angle finder for your maintenance team, this is the checklist I use to avoid expensive rework.

Who This Checklist Is For

Use this when you're comparing brands and prices, or when you already have a part number and only need to make sure the order is right. It also works when the request is vague. It doesn't replace engineering judgment; it keeps the purchase from skipping the details that cause returns.

Five minutes of verification beats five days of correction.

1. Ask What the User Will Actually Measure

The vague request is the most dangerous one. When someone says 'we need a thermal camera,' the real question is whether they need to spot hot surfaces or document temperature values. For a quick visual check, the FLIR One Gen 3 thermal camera can be enough. For an outdoor electrical cabinet or a fixed process point, you probably need a different unit with emissivity settings, a wider temperature range, and calibration traceability.

The same logic applies to a request for a weighing scale. Is it for shipping, production, or the lab? A legal-for-trade floor scale has different certification from a lab balance. If I don't know the job, I don't ask for a price yet. I ask one question: what will this measure, where will it live, and what will be done with the reading?

2. Check the Environment Before Comparing Datasheets

I learned this after ordering a sensor that had the right range and the wrong enclosure. It didn't fail instantly. It started acting up after washdown because I hadn't checked the IP rating. That kind of mistake feels small until it costs you a weekend.

Before buying any SICK sensor, I verify whether the location is exposed to washdown, dust, vibration, extreme ambient temperature, chemicals, or mechanical impact. A sensor that works on a dry assembly line may not survive in a food production line. The datasheet is useful, but it doesn't know your environment.

3. Match the Output to the Existing System First

This is the step I've seen skipped more often than any other. People compare measurement range and price, but not the communication interface. If you're looking at a SICK IO-Link encoder, ask whether your PLC or gateway actually supports IO-Link. If it doesn't, the diagnostics and parameterization that make IO-Link useful won't show up. You might only see position data, or nothing at all.

When I buy a SICK IO-Link encoder, I also confirm connector type, pinout, cable length, and whether the encoder is incremental or absolute. All of those details can matter more than the brand. In my first year, I ordered the correct part number from the website but the wrong interface. The supplier followed the paperwork perfectly. It still cost me a reorder fee and a bad conversation with the maintenance lead.

4. Verify Calibration and Required Paperwork

Measurement equipment is different from regular spare parts because the reading needs to be trustworthy. If a scale is used for shipping costs or acceptance criteria, the calibration matters more than the display. Before ordering an industrial weighing scale, I ask for the accuracy class and calibration certificate. If the supplier can't show it, the low price is not low.

The assumption is that an expensive instrument is accurate because it costs more. In my experience, it's the other way around: companies that build and test accurate instruments are able to charge more. You're paying for proof, not for a logo. Make sure the proof matches the exact model you plan to order.

If you need a documented temperature reading, a thermal camera is not a replacement for a real thermometer with calibration. A thermal imager is useful for finding hot spots, but a quality record often needs a verified contact probe or calibrated temperature sensor.

5. Plan for the Person Using the Tool

It's easy to buy a tool and forget the human side. Earlier this year, one of our teams requested a Starrett angle finder. The brand was specific, but the measurement job wasn't. If someone searches for how to use starrett angle finder, the tool is only part of the story. They also need to know which angle format to record and how to set the base before taking a reading.

I don't train installers, but I do ask the requester to explain the intended job before I order. If no one can show me the job, I ask more questions. A precision tool that sits in a drawer is more expensive than a simple tool that gets used.

6. Look at the Total Cost, Not Just the Unit Price

Part of my role is making the total cost clear. If we need a SICK encoder in three days because a machine is down, the expedite fee is a consequence of our lead time, not necessarily a supplier's greed. Rush orders are unpredictable, and unpredictability costs money.

This is where I got burned once by a cheaper quote on a weighing scale. The price was lower, but the quote lacked calibration documentation and didn't include the connector adapter we needed. After rework time and freight, the so-called savings evaporated. Never expected a lower quote to cost more. Turns out the hidden cost was in the details I hadn't verified.

Last Check Before Purchase Order

Part of me wants to consolidate the vendor list for simplicity. Another part knows that calibration, support, and documentation matter more than the logo. I compromise by using the same checklist every time.

Before I send a PO, I ask these questions:

• Have I confirmed the actual operating environment?
• Does the selected device communicate with our current controls?
• Is the calibration claim in writing for this exact model?
• Does the requester know how to use the device, or do we need training?
• Is the delivery date committed, not estimated?
• What is the rework cost if the spec is wrong?

The last question keeps me honest. It also follows the prevention-over-cure view I've developed after too many make-good orders: the five minutes spent double-checking are cheap compared with the five days after a miss. I know, because I've paid for both.