Test Pencil (145mm)

Name: Test Pencil (145mm)
Brand: Harden
SKU: 660001

Item No. 660001

Price on request

A test pencil is the simplest live-line indicator there is: a screwdriver-shaped probe with a neon lamp and a high-value resistor inside it. Touch the tip to a conductor, put a finger on the metal cap at the end, and if the conductor is live the lamp glows. At 145mm it is the pocket size — the one that lives in a shirt pocket or a pouch and gets used twenty times a day for the question "is this one on?"

The probe is quality steel, and the stated range is 110 to 250V AC, which covers Sri Lankan mains comfortably.

Now the part that matters more than anything else on this page, and we would rather say it than sell one to somebody who does not know it. A test pencil tells you when voltage is present. It does not prove that voltage is absent. The reason is in how it works: the neon lamp needs a tiny current to flow through the resistor, through your body and out to earth. If that path to earth is poor, the lamp will not light even on a fully live conductor. Standing on a dry wooden floor, on a fibreglass ladder, in rubber-soled boots, on an insulated mat — all of these can produce a dark lamp on a live wire. So can a flat battery of a different kind of tester, or simply not pressing the cap firmly enough.

The consequence is straightforward. Use a test pencil to find out which conductor is live, to check whether a circuit came back on, to identify a switched line — the everyday quick questions. Do not use it as your proof of dead before you put your hands on a conductor. For that, use a two-pole tester or a multimeter, and follow the discipline every electrician is taught: prove the tester on a known live source, test the circuit, then prove the tester again to be sure it was still working when it told you the circuit was dead.

The other honest note is about the screwdriver blade. It is a probe first and a screwdriver second. The shaft is thin, the tip is small, and the handle is not built for torque — using it to drive a stiff screw bends the shaft and can crack the insulation, which on a tool you deliberately touch to live conductors is not a small matter. Keep a real screwdriver for real screws.

The buyers are electricians and electrical technicians, appliance and equipment repairers, maintenance staff, building services and installation crews, and hardware dealers who sell them by the box.

Check the lamp against a known live point before you trust a dark reading, keep the shaft clean and dry, and replace it the moment the insulation is cracked or the cap is loose. Ask us on WhatsApp for a price by the piece or by the box, or for a two-pole tester if you need something to prove dead with.