In the industrial testing field, the phrase that equipment manufacturers dread hearing most is: “It seems there’s a problem with your product.”

Even more troublesome is this: the issue isn’t actually with your equipment, but the customer’s production has already come to a halt.

Recently, an engineer at Wuxi nGV Technology Co., Ltd.—Engineer Liu—encountered just such a situation.

Customer Urgent Report: Zero Offset Too High, Production Testing Stalled

A well-known large-scale motor test bench manufacturer in China has purchased Nagivolt’s high-precision current and voltage sensors. Its end customer is a prominent large motor manufacturing enterprise in China, which is using Nagivolt sensors in conjunction with power analyzers to conduct type‑test evaluations of motors.

Type testing is a critical step before a motor leaves the factory, and the accuracy of the data directly determines whether the product can be delivered in compliance with regulations. However, the customer suddenly reported that the test data showed a persistently elevated zero‑point reading, indicating an anomaly that prevented the test from proceeding normally.

The customer on-site is extremely anxious, as production schedules are tight; if the test bench shuts down, the entire downstream production line will be affected.

Remote analysis: Most likely not a sensor issue

Upon receiving the feedback, Nagifu’s sales engineer immediately conducted a remote consultation with the customer. Based on the customer’s description of the observed phenomenon and an assessment of the test system architecture, the Nagifu team’s preliminary analysis concluded that, given the sensor’s consistently stable zero‑offset characteristics, the issue was most likely attributable to the power analyzer’s settings, the signal conditioning stage, or the wiring connections.

In simple terms, the sensor’s “ruler” is accurate, but the “person” reading it may have selected the wrong range.

However, the remote guidance did not go smoothly; the customer’s on-site personnel were not sufficiently familiar with the power analyzer’s settings. Despite multiple adjustment attempts, the zero‑offset anomaly persisted. Anxious, the customer once again requested: Could an engineer be dispatched to the site?

Engineer Liu: Within a slightly plump frame lies a down-to-earth, hardworking “core”

Here, it is important to provide some background: Naji Fu is a standard‑product sales company whose core business is the R&D and manufacturing of high‑precision current and voltage sensors; it is not a system integrator. The sensors themselves are functioning properly; logically, the company could simply advise customers to contact a system integrator or the power analyzer manufacturer for resolution.

But Engineer Liu is different.

Engineer Liu is a “heavyweight” figure in our company—not because of his position, but because he truly carries considerable presence; as one colleague puts it, “When Engineer Liu stands there, he’s as steady as the zero point of our sensors.” Yet even more reassuring than his physical presence is his character: down-to-earth, diligent, and always striving to improve. He never lets a customer’s issue linger overnight, nor does he ever let a colleague’s request for help go unanswered.

Upon learning that the customer’s site was in a state of frantic urgency, Engineer Liu didn’t hesitate; he set aside the R&D work he was currently advancing and, patting his slightly protruding belly, said, “I’ll go—production is what matters most.”

On-site troubleshooting: a black-and-white striped T-shirt, a reassuring back view

Upon arriving on site, Engineer Liu was in no hurry to draw conclusions. Dressed in his signature black-and-white striped T-shirt, his sturdy figure moved back and forth between the test benches. Our accompanying colleagues discreetly snapped a few work photos—entirely from behind—since Engineer Liu was always immersed in his tasks and rarely turned to face the camera.

But it is precisely these silhouettes that make one feel especially at ease.

In the photo, he bends over with a slightly stout posture, inspecting each wire one by one and verifying every terminal. His black-and-white striped T-shirt sways back and forth in front of the instrument rack, resembling a diligent bee. Afterwards, he carefully scrolls through the power analyzer’s menu, meticulously comparing parameters such as channel configuration, range settings, and bias calibration.

Sure enough, the problem wasn’t with the sensor.

After a thorough investigation, Engineer Liu discovered that the zero-point calibration function of a certain channel on the power analyzer had been incorrectly enabled, and that the input coupling mode did not match the output signal type of the sensor, resulting in a fixed DC offset when no current was present at the input.

Engineer Liu wiped the sweat from his forehead, reconfigured the parameters, and performed the correct zeroing procedure. After powering up again, the data returned to normal, and the zero point was perfectly reset.

The on-site customer personnel heaved a sigh of relief: “Finally, we can resume testing!”

Post-Event Review: An “Extraordinary” Service Earns Deep Trust

After the issue was resolved, the customer gave Engineer Liu a big thumbs-up for his professional expertise and service attitude: “Not only are your sensors excellent, but your engineers are also highly reliable. This Engineer Liu, wearing the striped T-shirt, looks trustworthy—just as expected!”

For nGV, this business trip, though “exceptional,” was hardly surprising. After all, we have always believed that the challenges our customers face are precisely the challenges we must address—regardless of who bears the responsibility.

According to Engineer Liu, this also reflects Najib Razak’s stance

Later, someone joked with Engineer Liu: “It wasn’t even your fault—was it really worth making the trip? And you ended up drenched in sweat.”

Engineer Liu gave a simple, honest smile and said something very straightforward:

“When a customer buys our sensor, they’re placing their trust in us. Of course, it’s great that the sensor isn’t broken, but if the customer’s production line has stopped, I can’t just turn a blind eye. I may be a bit overweight, but I can still run. Helping the customer get the system up and running means they’ll come back to us for any future issues—now that’s the kind of long-term business we’re after.”

A colleague teased him, “It’s not that you can run—you’re running faster than anyone else.” Engineer Liu smiled again, revealing a row of white teeth: “Of course. Though we may be big in size, our sense of responsibility is even greater.”

A few photos of the back view, a warm-hearted engineer

At the end of this article, we will upload several photos of Engineer Liu at the job site. The images show only his back, with his face obscured—because Engineer Liu never pays attention to the camera; what matters to him are the wires in his hands, the data on the instruments, and the smiles on his customers’ faces.

Meanwhile, that black-and-white striped T-shirt has become a small hallmark at nGV’s after-sales service site. One customer later joked, “Next time I see the back of someone wearing a striped T-shirt, I’ll know it’s a nGV representative—and I’ll feel reassured.”

Conclusion

Wuxi nGV Technology Co., Ltd. specializes in the research, development, and manufacturing of high-precision current and voltage sensors. We may not always be able to make our sensors “never fail,” but we will certainly step up when our customers need us most!

It wasn’t our problem, but we went anyway. That’s because we have a team of dedicated, reliable engineers—quiet in speech but meticulous in their work. Even though it wasn’t part of our official responsibilities, we never said “no.”