SONOFF SNZB-02LD

Probe temperature sensor

A battery-powered Zigbee 3.0 thermometer with a 1.5 m probe rated from -40 to 115 °C and an IP65 host with a 2.2-inch LCD. It reads liquids and enclosed spaces such as fridges and tanks, and SONOFF states ±0.5 °C.

Zigbee

Probe temperature sensor

Compatibility

Compatible with EpiSensor Edge over Zigbee.

Pair it with the Zigbee radio on an EpiSensor Gateway. Edge reads it locally on the Gateway.

Edge reads 4 values from it, listed under Interface.

Connect it with

Gateway ZGW-20
From €899 ex VAT Configure Gateway

Specifications

The host is rated IP65 and for -10 to 60 °C and 0 to 100 % RH. SONOFF limits IP65 to splash-prone places: do not submerge the host, aim high-pressure water at it or leave it outdoors in the rain. The probe fixes in place with a hook-and-loop adhesive pad, and the host mounts on a metal surface with its magnet or hangs from its lanyard hole.^1, 2

Power: Battery. One 3 V CR2477 coin cell behind a twist-off battery cover.¹
Probe temperature range: -40 to 115 °C¹
Temperature tolerance: ±0.5 °C¹
Probe cable length: 1.5 m¹
Host working temperature: -10 to 60 °C¹
Host working humidity: 0 to 100 % RH¹
Ingress protection: IP65 (host)¹
Display: 2.2-inch LCD¹
Wireless: Zigbee 3.0 (IEEE 802.15.4)¹
Microcontroller: TLSR8656F512ET32¹
Dimensions: 62.8 × 58.5 × 21.8 mm¹
Weight: 86.2 g, including the probe cable¹
Enclosure: PC and ABS¹
Working altitude: Below 2000 m¹
Certification: CE, FCC, ISED, RoHS¹
Calibration offset: -50 to 50 °C in 0.1 °C steps³
Firmware updates: Over the air³

Where it is used

Fridges, chilled cabinets and incubators, with the probe inside and the host on the outside. The probe reads down to -40 °C, but the host is rated only from -10 °C.
Cold room and cold store temperature monitoring
Liquid temperature in tanks and containers, which SONOFF names as a use for the probe.
Legionella temperature monitoring
Enclosed spaces such as cabinets, where a probe through the door avoids opening them to read a display.

Interface

Readings and settings, with units and ranges where SONOFF publishes them. readable, readable and writable.^1, 3

Download

Reading	Unit	Range or values	Access
Measurements 1
TemperatureMeasured at the probe. The range is the probe’s rating.	°C	-40 to 115 °C	Read only
Settings 2
Display unitThe unit shown on the sensor’s screen. Readings reach Edge in °C either way.	-	`celsiusfahrenheit`	Read and write
Temperature offsetAdded to each temperature the sensor reports, in 0.1 °C steps.	°C	-50 to 50 °C	Read and write
Diagnostics 1
BatteryRemaining battery charge.	%	0 to 100 %	Read only

The display unit and the calibration offset are settings held on the sensor. Press the button on the back to wake it before you change either from Edge.³

Setup

Open pairing in Edge
In Edge, open pairing on the Gateway’s Zigbee network. The Gateway accepts new devices while pairing is open.
Power it on
Twist off the battery cover with a coin and pull out the battery insulation sheet. A new sensor enters pairing mode by itself and the signal icon on its screen flashes slowly.¹
Or start pairing by hand
The sensor leaves pairing mode after 3 minutes. To start again, press and hold the button with a card pin for 5 seconds until the signal icon flashes slowly. This also restores its factory settings.¹
Confirm the join
The signal icon stays on when the sensor has joined and goes off if pairing failed. Check that Edge identifies it as SONOFF SNZB-02LD.¹
Place the probe and check one reading
Fix the probe with its hook-and-loop pad where the temperature matters, then compare the reading with a reference thermometer beside the probe. Set the calibration offset from Edge if they differ.¹