Moes ZSS-QY-GL-U Zigbee natural-gas methane leak detector alarm

Which gas the detector notices. Mains natural gas is mostly methane; bottled gas is propane-butane. A detector designed only for methane may not react to bottled gas, and vice versa.

The gas concentration at which the alarm goes off, as a percentage of the LEL — the lower explosive limit, i.e. the smallest share of gas in air at which the mixture can ignite. The lower the figure, the lower the concentration the detector reacts to; for example, 8 % LEL for methane is about 0.4 % methane in air.

How long the sensor needs after power is applied before it starts measuring gas. During this time the detector does not yet monitor for leaks, so after a power cut it does not start working immediately.

After how many years, according to the maker, the device must be replaced: a CO sensor loses sensitivity over time. Whether this counts from first use or from the production date is given in the note.

The wireless link or network the device uses. Wi-Fi connects straight to the router; Zigbee, Thread and Bluetooth Mesh work through a hub or gateway.

Whether the device needs a separate hub, gateway or coordinator to work in a smart home. If so, it is sold separately unless stated otherwise.

The maker’s app used to set up and control the device.

The coordinator's maximum radio output. Higher power gives a steadier link to distant devices, but range in a home depends more on walls and the number of routers in the network.

Whether the detector can shut off the gas supply when there is a leak. A valve output on the detector itself (a relay or a solenoid-valve connector) works directly; “via automation” needs a hub, a separate smart valve or valve actuator and a configured scenario.

Volume of the built-in siren as stated by the maker; the distance it was measured at is given in the note. The same decibel figure at 3 m means a louder source than at 1 m; each extra 10 dB sounds roughly twice as loud.

Whether the device signals with a sound, an indicator or in the app that the sensor is faulty or has reached the end of its service life. EN 50291-1 requires such a signal; without it a faulty device looks the same as a working one.

Where the device gets its power: 230 V mains, an adapter, USB, batteries or a built-in battery.

The supply voltage (and current, if stated) as the maker gives it. It must match your mains or adapter.

Where the maker advises placing the detector. Methane is lighter than air and collects high up, so a methane detector goes near the ceiling; propane-butane is heavier than air, so the detector goes low, near the floor. The distance from the cooker and boiler is given by the maker.

How and where it is installed: in a wall box, on a wall or ceiling, on a DIN rail, on a table or in a socket.

The device’s size in millimetres as the maker states it. Check that it fits the wall box, niche or shelf.

The air temperature range the device is rated for. The lower limit matters outdoors, on balconies and in unheated rooms.

The rated relative humidity range, non-condensing.

The warranty period the maker states. Confirm warranty terms in Moldova with the seller.