Inside a battered carrying case, tucked away in a drawer no one had opened in years, sat a piece of history.

A few years ago, during an office move at HHK’s Namibia branch, someone slid open a drawer and found it: a Megger Earth Tester, model ET5, serial number 1038 M90025. Manufactured in March 1985 by Thorn EMI Instruments Ltd in Dover, England. Its green carrying case was worn nearly beyond recognition — scratched, scuffed, and beaten in the way that only decades of real field work can manage. An HHK sticker, faded but holding on, marked it as one of our own.
The instrument inside, though? Spotless.

That detail — worn on the outside, immaculate within — tells you something about the person who carried it.
But that ET5, as it turns out, was the newest of three.

A Different Kind of Precision

To understand what these instruments are, you have to understand what they do — and more importantly, how.
Each of these Megger earth testers uses what is known as the null balance method. There are no digital readouts, no automatic calculations, no shortcuts. The operator adjusts decade dials by hand, watching a galvanometer needle mounted on the face of the instrument. The goal is to bring that needle to absolute zero — to null. When it reaches null, the resistance reading on the dials is your answer, expressed in ohms.

It is a method that demands patience. It demands a trained eye. It demands someone who understands not just what the number means, but how to coax it from the earth itself.
The world moved on to digital instruments long ago. They are faster, easier, and more than capable of delivering accurate results. But there is something the null balance method carries that digital cannot replicate: the relationship between the operator and the measurement. Every reading was earned. Every result was a conversation between the technician and the ground beneath their feet.

Three Cases, Three Eras

At HHK’s Johannesburg headquarters, the stores department holds two of the three instruments. The third was the one found in Namibia — the ET5 that started this story.
The oldest is immediately recognisable for what it is: a classic brown leather case with a shoulder strap, green felt lining, and a small “M” emblem pressed into the front. Inside sits a Megger MN Earth Tester — black body, a single large dial knob, dual galvanometer display.

It comes with its original instruction booklet, still tucked inside: Earth Tester MN, Megger Instruments Limited. Based on its design, this instrument dates to the 1950s or 1960s. It was last calibrated in December 2019, certificate 105532-1 from an SANAS-accredited laboratory — proof that someone still trusted it enough to keep it current well into the 21st century.

The second instrument sits in a dark brown case, almost black, fastened with two key locks and a fabric strap. This is a Megger ET3/2 — multiple decade dials, an RΩ dial, a galvanometer. Its age falls somewhere between the MN and the ET5: likely 1960s to 1970s.

Both it and the leather-cased MN are stored at Johannesburg HQ, where they have been for years.
Then there is the ET5 — manufactured March 1985, found in a Namibia drawer during an office move, last officially calibrated on 24 May 2013 by an SANAS-accredited laboratory, certificate number 82747. The next calibration was due in May 2014.

Someone kept it in service well into the 2010s, long after its peers had been replaced by digital alternatives. That is not negligence. That is trust.

Helmut’s Work, In His Hands

All three of these instruments were used by Helmut Hermann Kanwischer — HHK’s founder — and by Nic, one of the longest-serving members of the HHK team, a man who worked alongside Helmut from the earliest days of the company and who, by any fair measure, became part of its foundations as much as any piece of equipment ever did.

Helmut started HHK in 1976 in a garage. He emigrated from Germany with a specialisation, a conviction that what he was doing mattered, and apparently very little regard for the limits other people might have accepted as reasonable. From that garage, he built what is now the largest lightning protection company in Southern Africa — eight branches, more than 100 specialists, projects spanning Namibia, Gauteng, the Northern Cape, and beyond. He served on SANS and IEC industry standards committees. He was a founding member of ELPA, the Earthing and Lightning Protection Association. He shaped the standards that govern how this industry works across a continent.

He carried a Megger tester to do it.

The Chimney on the Left

There is a detail that says more about Helmut than any formal biography could. HHK’s first project in Namibia was Van Eck Power Station in Windhoek. A coal plant constructed in the 1970s, it remains Windhoek’s primary power supply today — still running, still standing. Still protected. Every time Helmut drove past Van Eck in the years that followed, he would point it out. Not in a general way. He would point specifically to a particular chimney — “the one on the left, not the skew one on the right” — and remind whoever was with him that HHK had been there. That HHK had built something that lasted.

That kind of pride is not about credit. It is about care. It is the mark of someone who understood that their work had consequences — real, enduring, physical consequences for the people and infrastructure depending on it. A power station is not an abstraction. A lightning strike is not theoretical. Helmut knew this in a way that made everything he built feel personal.

He passed away in 2024.

What the Case Carries

The three instruments are kept as they were found: the leather-cased MN and the ET3/2 in the Johannesburg HQ stores department; the ET5 at the Namibia branch, in its worn green case with the HHK sticker still holding on, the instrument inside still clean. None are in active service. None have been put behind glass.

Together, they are the closest thing to a physical timeline of where this company began. The MN with its original instruction booklet, possibly older than some of the buildings HHK has since protected. The ET3/2, mid-century vintage, its key locks still working. The ET5, the last of the three to be calibrated, the newest and the most travelled — left in a drawer in Namibia, which is exactly where Helmut’s work had taken it.
The worn exterior of each case is every difficult site, every job done in heat or rain, every road driven to reach a project on time. The spotless instruments inside are the standard Helmut held himself to — and expected of everyone who worked alongside him.

Carrying It Forward

HHK is nearly 50 years old. The company Helmut built from nothing is now the definitive name in lightning and earthing protection across Southern Africa. It operates under the same SANS and IEC standards Helmut helped write. It holds the same sole focus — not a generalist electrical contractor, not a company that does earthing on the side, but a company that does nothing else and does it with scientific rigour from soil resistivity survey to Certificate of Compliance. That focus was Helmut’s choice. It shaped everything that followed.

The team that carries HHK forward does so knowing the weight of that history. Some of them worked with Helmut directly. Some of them learned from people who did. All of them work within a company whose entire existence is a reflection of one person’s conviction that protection — real, engineered, certified protection — matters enough to build a life around.

Three Megger testers. One from the 1950s or 60s. One from the 60s or 70s. One from 1985. None of them will take another reading. But the work they represent has never stopped.