Application Case: Transformer Thermal Inspection on a Fixed Maintenance Route

An anonymous electrical-maintenance case where the inspection distance, target size, optical field of view, and radiometric reporting led to a FLIR T865 camera-and-lens purchase.

Last updated: 2026-09-18

Project context

A data-center and industrial-plant maintenance contractor was asked to add transformer inspection to its quarterly energized-equipment route. The existing visual route identified panels and transformers but left too little space for close access to some terminations. The purchaser had received several offers for 640 x 480 cameras, yet no one had calculated whether the small connection points would be resolved from the permitted location.

How the inspection route was designed

The reliability engineer listed every asset, the normal load state, the closest permitted observation point, and the smallest component that could drive an action: bushing hardware, cable lug, radiator connection, or cooling fan area. Each view was assigned a standard distance and lens. Operators recorded load, ambient conditions, focus confirmation, emissivity/reflected-temperature assumptions, and a visible-light reference image.

Equipment selected

The team selected a FLIR T865 with 24-degree and 42-degree lenses because the combination covered most route assets while allowing an alternate optical view where a smaller target was farther away. The published 640 x 480 resolution, lens choices, radiometric image format, and reporting ecosystem suited the route. HIKMICRO G61 was included in the evaluation as a Chinese-brand option for clients that require a 640 x 480 industrial platform with locally supported workflow and lens verification.

Result in use

The first route did not find a dramatic hot spot, but it did reveal an important process gap: two images of the same lug had been taken at different distances and focus states, so their apparent temperature differences were not comparable. After the route card was standardized, a later increasing temperature trend at one termination became credible enough for a targeted maintenance check.

What to verify before publishing

Confirm the access distances, local energized-work procedure, and appropriate lens pair for your own customer segment. This is an anonymous real-world-style maintenance scenario with product recommendations, not a claim about an identified client.