Stop pricing sensors like it's 1985
I've been handling procurement and maintenance for industrial automation systems for over six years. In that time, I've made about eleven significant buying mistakes, collectively worth roughly $14,000 in wasted budget—not counting downtime. Now I keep our team's pre-purchase checklist, because I don't want anyone else repeating what I did.
Here's my blunt opinion: the cheapest part is the most expensive thing you can buy. Every time I ignored that rule, I paid for it—sometimes twice.
Lesson one: the $800 "bargain" that cost $5,200
In February 2019, I had a machine down with a failed photoelectric sensor. The OEM part from SICK was going to take four days. A third-party "compatible" sensor was available locally—and it was 40% cheaper. I knew I should wait. But I thought, "What are the odds it fails?"
Well, the odds caught up with me. The replacement lasted 74 days before its lens fogged up in a humid environment. The original SICK sensor in that position had run for four years without a problem.
Let me show you the math:
- Third-party sensor: $180
- Emergency replacement order (genuine SICK): $320 including freight
- Line stoppage: 6 hours × $600/hour production value = $3,600
- My maintenance team's overtime: $1,100
- Total: $5,200
The original SICK quote had been $490. Even if it failed once in year three instead of year five, the arithmetic still points to the OEM part. That was the moment I started calculating total cost of ownership, not unit price.
Lesson two: TCO is arithmetic, not vibes
Total cost of ownership includes the base price, but also setup, commissioning, calibration, maintenance, risk of downtime, and the cost of getting the specification wrong. I've seen this bite people in three areas specifically:
PMD 3D sensors are not "just cameras"
If you're choosing a PMD 3D sensor for object detection or volume measurement, a cheap model may appear to work in a demo. But the real cost appears when you need robust performance under changing light, varying surface reflectivity, or vibration. A SICK PMD 3D sensor is not just hardware—it's the software, the pre-tested parameter sets, and the support when something odd shows up in the data.
I once watched a team spend three weeks trying to tune a low-cost 3D sensor on a robotic picking station. They replaced it with a SICK unit. Commissioning took two days. The three weeks of an automation engineer's salary was more than the price difference. That's a TCO gap you can't see if you only compare datasheets.
CO2 sensors: accuracy is a maintenance cost
For CO2 sensors in HVAC or lab monitoring, TCO includes calibration frequency and drift. A cheap NDIR sensor may save $150 upfront but require manual zero-calibration every two months. A better sensor holds accuracy for 12+ months. If your application is tied to indoor air quality compliance, the cost of inaccurate readings goes beyond the sensor itself.
As of January 2025, the SICK CO2 sensor lineup includes dual-channel models designed for long-term stability. The point isn't that every cheap sensor is bad—it's that you can't judge based on the purchase price alone.
The hidden cost of the search box
Here's an angle that surprised me: search confusion has a measurable cost.
Some people type "sick real thermometer high fever" or "home sick" into Google and they're looking for medical information. But an engineer typing "SICK" is looking for an industrial sensor manufacturer. If those two searches get muddled, the buyer may land on the wrong product pages and lose hours of research time.
I've seen colleagues waste half a day trying to find a replacement part because they didn't include the right model number in their search. That time is also a cost. TCO thinking means counting the hours spent on sourcing, evaluating, and troubleshooting—not just the invoice total.
The Eppendorf Repeater pipette example
It's not just sensors. Consider the Eppendorf Repeater pipette. If you've ever asked "how to use Eppendorf Repeater pipette" and gotten a confusing answer, you know the feeling. The right technique—attaching the tip firmly, aspirating slowly, dispensing with steady pressure—is simple once you see it. But if you buy a knockoff or skip the training, you get inconsistent volumes, wasted reagent, and ruined experiments.
I remember watching a lab technician use a manual pipette for repetitive work because "the Repeater seemed complicated." After twenty minutes of practice, she realized it cut her time per plate in half. The tool wasn't overpriced—it was just undersold.
Eppendorf's official instruction manual (accessed April 11, 2025) shows the proper procedure in minutes. The cost wasn't the device; it was the temporary ignorance about how to use it. That's a TCO concept too: knowledge is part of the acquisition.
What about the usual pushback: "SICK is too expensive for us"
I hear that a lot. And I get it—budgets are real. But consider what "expensive" actually means.
I'm not saying every SICK product is right for every application. Sometimes a basic sensor is enough. But too many teams default to the lowest bidder without calculating the cost of failure. The plant manager who says "we can't afford SICK" is usually the same person who approves overtime for emergency repairs without flinching.
Look, I was that person. In my first year, I purchased six low-cost proximity sensors to "save money" on a renovation. Three of them failed within 18 months. I still kick myself for that one. If I'd counted the re-installation labor and the production interruptions, the SICK units would have paid for themselves.
The SICK brand is well known for its encoder and safety sensor technology. But the real value isn't in the name—it's in the reliability data, the application support, and the reduced likelihood of unplanned downtime. That predictability is what you're actually buying.
Single price is a fiction. TCO is the truth.
Let me make this as clear as I can: price is what you pay. Cost is what you live with.
The next time someone hands you a quote, don't just look at the number. Ask about the installation. Ask about the failure history. Ask about the last time the operator had to tweak it. Ask how many hours you'll spend searching for answers. Those are not abstract risks—they're line items.
I still catch myself slipping into "what's the cheapest" mode. But I've got a checklist now, and the first line is: Calculate the total cost, not the sticker price.
That's what experience taught me. And it only took $14,000 in mistakes to learn it.
