A pen that says nothing is not the same as a circuit that is dead
A voltage pen detects the electric field around a live conductor without touching it, which makes it the fastest tool in the box and the easiest to misread. It answers "there is probably voltage here", never "this is safe" — insulation thickness, screening and the way it is held all change what it senses. A self-test function matters more than sensitivity, because it is what tells you the pen still works. We compare stated detection range, adjustable sensitivity, self-test, torch and audible alert, and the manufacturer's stated category.
12–1000 V AC · CAT III 600 V stated · LED indication
A 12 to 1000 V AC contactless pen stating CAT III 600 V, with LED indication and an instruction to test the pen before each use.
Best for: A pocket first check, always followed by a two-pole tester before any work.
≈ $10
12–1000 V AC · auto and manual modes · stepless sensitivity · 8 LEDs in 3 colors
A detector with continuously adjustable sensitivity and an eight-LED, three-color strength display, so field strength is read as a scale rather than as a yes or no.
Best for: Picking one live conductor out of several, where a single-threshold pen lights up on all of them.
≈ $16
50–1000 V AC · CAT III 1000 V stated · LED, buzzer and vibration
A 50 to 1000 V pen stating CAT III 1000 V, alerting by LED, buzzer and vibration, and usable for tracing a break in a wire.
Best for: Tracing cables and identifying the live conductor in noisy or poorly lit conditions.
90–1000 V AC · single-pole · finds breaks, blown fuses and faults
A trade detector covering 90 to 1000 V AC, stated for locating live conductors, cable breaks, blown fuses and defective components.
Best for: A trade pocket detector for mains work, where nothing below 90 V is in scope.
90–1000 V AC · flat tip · industrial reference
Fluke's industrial detector, 90 to 1000 V AC with a flat tip. The listing states almost nothing beyond the range and the form.
Best for: A workshop standardized on Fluke, where the catalog reference is worth more than the listing.
≈ $36
The detection range decides what the instrument signals. Below its threshold it stays silent, which proves nothing.
A tester that only flashes goes unnoticed above head height on a working site. A stated audible alarm decides how reliably the warning gets through.
A non-contact tester can fail silently, and the absence of a signal proves nothing. A stated self-test function is what lets you check the device on a known live source before each use.
No, never. A screened conductor, deep in a chase or behind an obstacle, may trigger nothing. Only a two-pole tester confirms an absence of voltage.
Static electricity and neighboring fields cause triggering. Adjustable sensitivity strongly reduces those false positives.
On a known source, every time. An instrument with a weak battery can stay silent in front of a voltage that is present.
Sometimes, very approximately. A dedicated cable detector is built for that task.
These instruments detect an alternating field. A DC installation does not trigger them.
Metal screens it. One of the situations where an absent signal is misleading.
For quickly picking out a live conductor among others, without touching anything. A locating tool, and very useful in that role.
A live conductor alongside induces a field strong enough to trigger the device. A non-contact tester indicates a possible presence, never a certain absence.
An absent signal never proves an absence of voltage: screening, depth or metal are enough to silence the instrument. It is a locating tool, never a confirming one — that function belongs to the two-pole tester, and to it alone.
A column is raised only if four instruments in five publish the value. Below that, it would be measuring the silence of the manuals.
| Model | Price | Voltage measurement |
|---|---|---|
| Neoteck TL163-US | $10 | 12–1000 V AC |
| BSIDE AVD06 | $16 | 12–1000 V AC |
| Fluke FLK2AC/90-1000V | $36 | 90–1000 V AC |
| PeakTech P 1030 | — | 50–1000 V AC |
| Wiha 43798 | — | 90–1000 V AC |
Specifications: manufacturer sheets for measuring instruments and the matching Amazon product pages. Prices and availability: Keepa. Every figure in this table names its source.
Most recent revision in this category: August 31, 2026.
Prices quoted in these summaries are dated readings. The live price is shown next to each product.
