How to Set Walk-Through Metal Detector Sensitivity

Short answer

Nine times out of ten a badly behaved walk-through detector is a siting problem, not a parameter problem. Fix the location first — two metres from fixed metal, five from movable metal, one to two from electrical interference — then walk the sensitivity down with a sample method. Turning the global sensitivity to 300 makes it worse, not better.

Step 1: the distances that decide everything

The floor must be flat and rigid. If the gate rocks when people walk past, no setting will be stable.

Step 2: confirm the gate is stable

Three checks, all of which must pass before you touch a parameter:

• One minute after power-on the panels no longer sway (the self-test needs about a minute to reach working state)
• A person carrying no metal walks through without an alarm
• Repeated passes give the same result

Step 3: the sample method

The goal is a gate that ignores everyday metal but always catches the contraband you care about:

1. Pick a small metal object as the sample — a bunch of keys works well. This is your "must not alarm" threshold
2. Raise the sensitivity until the sample alarms on every pass
3. Lower it step by step, testing the sample each time
4. Stop at the point where the sample just stops alarming
5. Adjust only the zones that need relaxing, not the whole gate

The result: anything smaller than the sample passes, anything larger alarms reliably. This is far more precise than picking a round number for global sensitivity.

What you can actually adjust

The settings menu is password protected. Change the factory password and record who holds it.

Step 4: troubleshooting false alarms in order

1. Environment — any large metal within 1.5 m, any draught through the gate
2. Lower the sensitivity — global first, then per zone
3. Change the frequency — shift within 0–99 to step around external interference
4. Look for inverter-driven equipment — lifts and injection moulding machines interfere badly while running
5. Relocate — if the first four steps fail, moving the gate usually solves it

Step 5: the queue rules matter as much as the settings

• Paint a waiting line 50 cm before and after the gate, one person at a time
• Keys, phones, coins and badges go into a tray before passing
• Walk at normal pace; no running, no lingering, no touching the panels
• The next person waits until the alarm stops
• Use the zone lights to locate the metal, then confirm with a handheld detector

High-security sites also need a dress code: metal hair clips, earrings, necklaces, buckled belts, jeans with metal rivets and steel-toe boots all alarm. Issue workwear without metal fittings where possible.

FAQ

The gate does not count people. Check the panel probe connectors first, then look for infrared interference (monitors, remote controls, direct sunlight); if both are clear, replace the infrared sensor.

Is higher sensitivity better? No. Higher sensitivity means more false alarms, and guards start ignoring the gate — which defeats the purpose entirely.

Why does a newly installed gate alarm constantly? Almost always siting: a roller shutter at the entrance, a lift opposite, or a draught. Measure the distances before touching any parameter.

We forgot the password. Contact the manufacturer to reset it; then change it and record the holder.

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