Today a customer came to our factory in person to test a sample. Not to look at a catalogue, not to sit through a presentation — to stand at the bench, watch the measurements being taken, and decide on the spot. The sample passed, and their feedback was immediate and positive.

This is worth writing about, because supplier selection in our industry is still mostly conducted through email threads and PDF attachments, and that process has a hidden cost that nobody puts in the quotation.

What Email-Based Sample Approval Actually Costs

A typical remote approval runs like this: drawings are exchanged, a sample is shipped, the buyer measures it, a question comes back, measurements are repeated on both sides, a photo is taken at a questionable angle, and two weeks disappear. Nothing is wrong with either party — it is simply that measurement disputes are almost always resolved faster in person than in writing.

When the customer is standing at the bench, that loop collapses. If a force reading looks low, the gauge is re-zeroed in front of them. If the stroke definition is ambiguous, the fixture is adjusted and measured again. The argument does not happen, because the data is produced once, jointly, and agreed on the spot.

What Happened During This Visit

The part under test was our DC24V medical bed electromagnet — a medical device actuator specified at ≥ 300 g force at a 5.8 mm stroke, 18.48 W at DC24V on a 31 Ω ±10% coil, with a nominal duty of 0.05 s ON / 0.15 s OFF and continuous energisation permitted for up to 300 s, rated for over 500,000 cycles.

The visit covered the checks that actually decide a medical device approval:

• Force at the working stroke. Measured at 5.8 mm — not at contact — and repeated across several units so the customer saw consistency, not one lucky reading.
• Extended energisation. The coil was held powered beyond the nominal duty cycle while temperature was observed, confirming the 300 s allowance in practice rather than on paper.
• Insulation resistance and dielectric strength. DC500V insulation measurement between coil and bobbin, and a dielectric test with leakage held within 1 mA — the numbers their approval file depends on.
• Cyclic operation. Repeated actuation to confirm force does not drift and the release stays clean.
• Appearance and workmanship. Inspection for damage, cracking, rust and surface staining as a production acceptance criterion.

Beyond the Bench: Walking the Line

A sample test proves a part; it does not prove a process. So the visit also went through the parts of the factory that determine whether unit 5,000 matches the sample: coil winding and resistance control, assembly and fixture discipline, the electrical test station, incoming material verification, and the documentation trail that ties a serial number to its test record.

For a buyer, this is the part of a factory visit that is usually more valuable than the sample itself. Anyone can produce one good sample. The question is whether the process can repeat it next quarter, after a material batch change or a staff rotation.

The Result

The sample passed the test on the day, the customer expressed clear satisfaction with both the performance and the way the testing was conducted, and the project moved forward on that basis. No measurement disputes followed, because there was nothing left to dispute.

An Open Invitation

If you are qualifying a solenoid or a stepper motor for a medical, optical or textile application, you are welcome to do what this customer did: come and test the sample on our bench, with your own gauge if you prefer, and walk the line while you are here. If travel is not practical, we will run the same test sequence on video with you live — the point is that the data is produced jointly, not asserted afterwards.

Tell us which specification you need verified and when you would like to visit — we will set up the bench, the fixtures and the documentation in advance.