Electronics and water don't usually mix - which is why liquid level sensing projects can be a little challenging. You can DIY a sensor but keeping it clean and un-oxidized can be a pain. The Optomax Digital liquid level switches are a clever solution for when you need a small sensor to detect liquid/water: super easy to use and very durable too!
Inside the plastic sensor casing is an infrared (IR) LED and matching photo transistor. When in the open air, the IR light bounces back to the sensor so you know its nice and dry. When the sensing tip is immersed in liquid, the IR light escapes, and the transistor turns off. The sensor can detect the presence or absence of almost any liquid type; oil or water based. It is insensitive to ambient light and is not affected by foam when in air or by small bubbles when in liquid.
The microcontroller-friendly logic level output is push-pull type, and can sink and source up to 100mA at a supply voltage range of 4.5 to 15.4VDC - so you can even use it to directly control a transistor or perhaps even a small relay.
Simply connect the Blue/Black wire to ground, the Red wire to 4.5-15.4VDC and look at the output with your multimeter or microcontroller. When dry the output is the same as the red wire. When wet, the output is 0V. Note they're pretty sensitive, any liquid on the sensor (e.g. droplets on the surface) can trigger it.
Comes in a chemically resistant Polysulfone housing material – the standard choice for most applications – for external sensor mounting and for use in standard operating temperature ranges (-25 to 80°C).
- Reverse polarity, ESD and transient over-voltage protected
- Wide supply voltage range
- Push-pull output, capable of sinking or sourcing up to 100mA, can directly drive small loads
- Solid state, fully enclosed, so no moving parts to cause unreliability
- Small in size so they can be installed in applications where space is limited
- Can detect tiny amounts of liquid when positioned correctly, ideal for leak detection
- Fast response time
- Repeatable switching point
- Built-in output delays available on request for applications where sloshing causes intermittent switching
- Very robust permitting use in a wide range of fluids and chemicals
- See datasheet in Technical Details for more specs and info!
Weight: 8.4g / 0.3oz
Wire length (not including sensor): ~240mm / ~9.5"
Documentation and Resources:
Exact shipping can be calculated on the view cart page (no login required).
We deliver Australia-wide with these options:
- $3 for Small Items (3-7 days, not tracked, only available on selected small items)
- $6.95 for Standard Post (2-4 days, tracked)
- $8.95 for Express Post (Overnight for Australia Post Next Day Network, tracked)
- Pickup - Free! Only available to customers who live in the Newcastle region (only after we email you to notify your order is ready)
International Orders - the following rates are for New Zealand and will vary for other countries:
- $11.49 for Pack and Track (3+ days, tracked)
- $16.50 for Express International (2-5 days, tracked)
If you order lots of gear, the postage amount might increment based on the weight of your order.
Our physical address (here's a PDF which includes other key business details):
Unit 18, 132 Garden Grove Parade
Take a look at our customer service page if you have other questions such as "do we do purchase orders" (yes!) or "are prices GST inclusive" (yes they are!). We're here to help - get in touch with us to talk shop.