TMR-04 Isolated-Ground TM Probe (ABS capsule)
Copper contacts in an ABS capsule — the key ground never touches the panel.
Every other probe on this page conducts the key's ground return straight into the panel it is bolted to. This one does not: the copper contacts sit inside a moulded ABS capsule, so the TM ground is electrically isolated from the mounting surface. That is the fix for the ground loop you get when a metal probe body meets a metal door, kiosk or machine panel that already shares a ground with the controller — a fault that shows up as intermittent reads nobody can reproduce on the bench. The self-aligning face guides the key onto the contact, and the M12 threaded neck fixes through the panel with a single nut.
The only probe that keeps ground off the panel
This is not a cosmetic difference — it decides whether the installation works. A metal-bodied probe such as the TMR-02 grounds itself through its fixing nut, so its datasheet has to warn that the panel must be non-conductive. Plenty of real doors are not: steel entrance plates, aluminium kiosks, machine enclosures, vehicle dashboards. Bolt a metal probe into one of those and the key's ground return finds a second path back to the controller, and reads start failing in ways that look random. The ABS capsule removes that path entirely, which is why the TMR-04 is the version to specify whenever you cannot guarantee what the probe is being screwed into.
Key features
- ABS capsule electrically isolates the key ground from the mounting panel — no ground loops in metal enclosures; the right choice wherever device GND and data GND must stay isolated.
- Mounts straight onto a metal panel with no additional insulation — the GND path is fully insulation-wrapped inside the capsule.
- Chrome-plated copper contacts on an all-metal contact face — rated for over a million touch cycles; self-aligning entry guides the key.
- Virgin-resin plastic parts resist wear and ageing; full-gauge copper-core lead to national cable standard keeps the signal stable — factory-direct, export-grade build.
- Ø24.01 mm face, Ø19.05 mm contact ring, 10.8 mm front depth, 22.37 mm body; M12 threaded neck with ABS fixing nut for easy installation.
- 215 mm two-wire lead with tinned ends — black GND, red DATA; TMR-04A adds a green/red dual LED on a four-core lead.
Product video
Specifications
| Chip / compatibility | Factory model TMR-04 · reads all DS1990A / TM1990A / RW1990-class keys |
|---|---|
| Package | Chrome-plated copper contacts in a moulded ABS capsule — GND isolated from the outer case · Ø24.01 mm face, Ø19.05 mm contact ring, 10.8 mm front depth, 22.37 mm body · approx. 25 × 3 × 3 cm overall incl. lead, net weight ≈18 g |
| Mounting | Panel mount, M12 threaded neck with ABS nut — fits straight onto metal panels, no extra insulation needed; 215 mm two-wire lead (black GND, red DATA), tinned ends, no terminal |
| Protocol | 1-Wire® |
| Operating temperature | −40 °C … +85 °C |
| Options | TMR-04A adds a green/red dual LED on a four-core lead; cable length, connector and capsule colour to order |
Product dimensions
Ordering information
| MOQ | 100 pcs |
|---|---|
| Lead time | 3–7 days for stock items, 10–15 days for OEM |
| Packing | Bulk ESD bags (100–200 pcs/bag, 2 bags/carton); blister or header cards for retail on request |
| Samples | Free samples for volume buyers — courier at cost |
| Payment | T/T bank transfer; other terms negotiable for repeat orders |
| Shipping | DHL / FedEx / UPS air express; sea or rail freight for pallet volumes |
| Customization | ROM ranges · housing colours · laser logo · private label |
Typical applications
Related products
TMR-01 Copper TM Probe
Chrome-plated copper probe with pre-wired leads — the minimal front-end.
TMR-01A Copper TM Probe with Guide Ring
The TMR-01 with a polymer guide ring — the key lands on the contact first time, every time.
TMR-02 Panel-Mount TM Probe (DS9092 compatible)
DS9092-compatible panel probe with M18×1 nut and 200 mm leads — the industry-standard front end.
TMR-02-4P Panel Probe with LED (DS9092L compatible)
The TMR-02 with a built-in LED — four wires, so the controller can light the ring on a valid read.