From Hand Cranks to Bluetooth: The Evolution of the Megohmmeter

I saw him the other day, a young technician, probably fresh out of trade school, assigned to test the windings of a massive 500-horsepower motor. He walked up to it holding a compact, bright yellow device in one hand, something that looked more like a tricorder from Star Trek than a piece of industrial test gear. He clipped on a few leads, tapped a button on the screen, and stood back, arms crossed. A minute later, his phone buzzed. He glanced at it, nodded, and started packing up.

And just like that, he was done. I couldn’t help but chuckle, shaking my head as a flood of memories came rushing back. That kid had no idea. He had no idea about the sweat, the strain, the art form that this simple, vital task used to be.

The Symphony of the Hand Crank

In my day, when you were told to “Megger” that same motor, it was a two-man job. Our “Megger” wasn’t a one-pound box of magic. It was a beast. It lived in a heavy wooden or Bakelite case with a thick leather strap that dug into your shoulder. It weighed a good ten, maybe fifteen pounds.

The procedure was a well-rehearsed symphony. I, as the senior electrician, would connect the thick, braided leads. My apprentice would get into position next to the box. His job was the most important and the most grueling: he was the engine.

“Alright, Jimmy,” I’d say, “start cranking. Smooth and steady now.”

Out would fold the hand crank, and he’d begin to turn. It wasn’t about speed; it was about rhythm. You had to crank at a constant rate, usually around 160 rpm, to generate the stable 500 or 1000 volts needed for the test. Crank too slow, the voltage would drop. Crank too fast, you’d overshoot. All the while, I’d be crouched by the motor, one eye on the analog meter’s wavering needle, the other on my watch’s second hand, yelling out timings.

The air would fill with the whirring gear-sound of the generator and the faint smell of ozone. Jimmy would be breathing hard, sweat beading on his forehead. It was a physical act, a connection between muscle, machine, and measurement. There was a certain pride in it, in mastering this quirky, demanding dance. But let’s be honest, it was hard, cumbersome work. And if your hand slipped and you touched a lead while it was energized… well, it would certainly wake you up.

From Muscle to Microchip

And now I watch this kid. Let’s compare his Tuesday morning to my Tuesday morning, circa 1985.

• The Burden: He carried a one-pound Megger MIT2500. I lugged a fifteen-pound box that felt like an anchor.
• The Manpower: He worked alone. I required an apprentice, whose main job was to serve as a human motor.
• The Reading: His result was a stable, backlit digital number, locked on the screen, accurate to the decimal. My result was an estimation, trying to average the subtle dance of a needle on a mirrored scale.
• The Report: His test data was automatically saved, complete with a time stamp, and probably already synced via Bluetooth to a report on his laptop before he even coiled his leads. My report was a smudged entry, scribbled in a paper logbook with a pencil.

He performed a more accurate, more reliable, and fully documented test in about a quarter of the time, with zero physical effort. That’s not just progress; that’s a revolution.

The Unchanging Heart of the Mission

But as I watched him walk away, I wasn’t resentful. I was, strangely, proud. Because for all the incredible differences in our tools, the heart of our mission was identical. He, like me, was there for one reason: to verify the integrity of an invisible shield. To ensure that the immense power contained within that machine stayed where it belonged, keeping the motor running, the factory producing, and, most importantly, the people working around it safe.

The “how” has been transformed by genius engineers and relentless innovation. The heavy box has become a smart device. The muscle has been replaced by a microchip. But the “why” remains exactly the same.

I walked over. “Nice piece of kit you’ve got there,” I said, nodding at his yellow meter.

He smiled. “Yeah, it makes life easy. My instructor told us stories about the old hand-crank ones. Said they built character.”

“Oh, they did,” I laughed. “They certainly did.”

And in that moment, I knew the craft was in good hands. The tools have changed, but the purpose endures. And frankly, my back is thankful for it.