Milesight WS303 Mini Leak Detection Sensor
Authorised Milesight UK Distributor£41.90 ex VAT (£50.28 inc. VAT)
The Milesight WS303-868M is a compact LoRaWAN leak detection sensor with an integral water probe and buzzer. It alarms once conductive liquid reaches a level of 0.5 mm at the probe. IP67 rated and 63 × 63 × 14 mm, it runs around 5.7 years on one 590 mAh CR2450 cell and supports Milesight D2D for direct control without a gateway.
Trigger ConditionOnce liquid level reaches 0.5 mm
Need the gateway too? Build and price the whole kit →
In stock · typically dispatched within 14 working days from the UK
Kits that use this part: Server room monitoring kit · Vacant property monitoring kit · Plant room monitoring kit
● Quotes answered within one working day · UK support
Delivery & assurance
- Ships from the UK
- £14.25 flat UK delivery
- Secure checkout — card, Klarna, invoice
- Manufacturer's warranty
Questions about this product? Call our UK team: 023 9223 3611
Description
WS303 is a tiny and mighty leakage detection sensor for detecting
presence of water leaks and transmitting an alarm using LoRaWAN®
technology. With this low power consumption technology, WS303 can
work up to 5 years with a 590mAh battery.
Compliant with Milesight D2D protocol, it can directly link with other Milesight devices to realize danger prevention and effectively prevent unnecessary loss. The wire-free WS303 can be easily used in smart offices, buildings, and houses.
Users can receive real-time alarms via a built-in buzzer locally
and a mobile App remotely. Combining with Milesight LoRaWAN®
gateway and Milesight IoT Cloud, users can manage all sensor data
remotely and visually.
• Features
• Detect the presence of conductive liquids using a small water probe
• A replaceable built-in 590mAh battery with up to 5 years of life for wire-free power supply
• IP67 waterproof enclosure for harsh environment applications
• Embedded with a buzzer for real-time alarming
• Support Milesight D2D protocol to enable ultra-low latency and direct control without gateways
• Equipped with NFC for easy configuration
• Compliant with standard LoRaWAN
® gateways and network servers
• Quick and easy management with Milesight IoT Cloud solution
Detection:
Liquid Type: Conductive Liquid Trigger Condition: Once Liquid Level Reaches 0.5mm
Additional information
| Weight | 0.036 kg |
|---|
WS303-868M specifications
| Trigger Condition | Once liquid level reaches 0.5 mm |
|---|---|
| Liquid Type | Conductive liquid |
| Local Alarm | Built-in buzzer |
| Technology | LoRaWAN®, Milesight D2D |
| Frequency | CN470/IN865/RU864/EU868/US915/AU915/KR920/AS923-1&2&3&4 |
| Tx Power | 16 dBm (868 MHz)/20 dBm (915 MHz)/19 dBm (470 MHz) |
| Sensitivity | -137 dBm @300bps |
| Mode | OTAA/ABP Class A |
| Antenna | Internal antenna |
| Power Supply | 1 × 590 mAh CR2450 lithium battery (replaceable) |
| Battery Life | Around 5.7 years (one hour leakage per week, 25°C) |
| Operating Temperature | -10°C to +60°C |
| Relative Humidity | 0% to 100% (non-condensing) |
| Ingress Protection | IP67 |
| Dimensions | 63 × 63 × 14 mm |
| Weight | 36.4 g (battery included), 29.8 g (battery excluded) |
| Material & Colour | ABS+PC, White |
| Installation | 3M tape mounting, desktop |
| Configuration | Mobile app via NFC, or downlink |
| Advanced Features | Milesight D2D controller, water leakage alarm |
| Approvals | CE, FCC; RoHS |
Specifications taken from the manufacturer datasheet.
Which version do I need?
The -868M part number is the 868 MHz build. The datasheet lists EU868 among the supported frequency plans and quotes 16 dBm Tx power at 868 MHz. UK LoRaWAN uses EU868, so -868M is the correct UK variant.
Typical applications for the WS303-868M
- Smart office and building leak detection
- Under-sink and plant room water leak alerts
- Server and comms cupboard leak detection
- Domestic and light commercial leak monitoring
- Triggering a Milesight D2D shut-off device on a leak event
Buying guides for this product
Frequency band
Supplied on EU868, the LoRaWAN band used in the UK and across Europe. That is the default and you do not need to ask for it — the -868M in the part number is the EU868 build.
The same WS303-868M unit also covers IN865 and RU864. Those bands share the 863–870 MHz radio with EU868, so one device can be set to any of them in its own configuration — no different part number needed.
CN470, US915, AU915, KR920 and AS923 are a different radio and therefore a different build. Milesight makes them and we can order them: tell us where the devices are being deployed and we will confirm the part number, price and lead time.
Not sure which band applies where? The Things Network publishes the LoRaWAN frequency plan for every country.
Complete the stack
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WS303-868M — frequently asked questions
How much water does it take to set off the alarm?
The trigger condition is a liquid level of 0.5 mm at the probe, for conductive liquids.
Does it alarm locally as well as over the network?
Yes. It has a built-in buzzer for real-time local alarming, in addition to the LoRaWAN uplink and mobile app notification.
What battery does it use and how long does it last?
One replaceable 590 mAh CR2450 lithium cell, rated for around 5.7 years at one hour of leakage per week at 25°C.
Can it trigger a valve or another device without a gateway?
It supports the Milesight D2D protocol as a D2D controller, which lets it directly link with other Milesight devices at ultra-low latency without a gateway. For network reporting it uses standard LoRaWAN gateways and network servers.
How is it mounted and how big is it?
63 × 63 × 14 mm, 36.4 g with battery, fixed by 3M tape or simply placed on a surface. It is IP67 rated with an operating range of -10°C to +60°C.
How much does the Milesight WS303 Mini Leak Detection Sensor cost in the UK?
The Milesight WS303 Mini Leak Detection Sensor is £41.90 ex VAT from Indiott, a UK distributor. The price is published rather than quote-only, and we invoice with VAT (PSI Technologies Ltd, VAT GB 730 2340 83). UK delivery is a flat £14.25 per order ex VAT, whatever the weight.
What is the lead time and delivery cost for the Milesight WS303 Mini Leak Detection Sensor?
The Milesight WS303 Mini Leak Detection Sensor is in stock and typically dispatched within 14 working days from the UK. UK delivery is a flat £14.25 per order ex VAT, whatever the weight or how many items you order. We ship to GB and the EU and provide a VAT invoice with every order.
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