Water flow/ pressure sensor. Ideal for CO2 laser water protection

Price: $7.50
189 units available
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This is a pressure type water sensor that detects whether water is flowing or not. It is a simple device but works well. The triggering pressure is adjustable by turning a knob.

The device is ideal for water flow detection in CO2 laser machines. Once water is flowing through a "T" connector, the normally open contact becomes a closed contact. It comes with a free "T" connector.


T connector outer diameter: 10mm

Average rating 6 out of 10 ( based on 9 reviews )

Good, but could be better.

Review by Dave on 2/10/2020

With NO documentation, it was only good mechanical aptitude that allowed me to get it installed and working. 1. The adjustment worked exactly opposite from what I expected. Adjusting the plunger all the way in was the most sensitive. But once turned to press as far as possible, it switched with the flow from my aquarium pump supplied with my laser cutter. 2. So the switch body has a 1/4" connector, and all my tubing and fittings on the laser and the supplied T fitting are 3/8". Not a major difference, but not something to just slip together. It did, how ever, come with a short piece of 1/4" silicone tube. After a bit of looking and head scratching, I discovered the magic combination. Slip a short piece of the 1/4" over the valve fitting with a little left over to make a 'funnel' tip. Wipe a bit of skin oil on the 1/4" silicone to be able to wiggle and press the 3/8" silicone over the 1/4" silicone, and I now had a water and low pressure tight connection.

Works perfectly

Review by Fred on 1/16/2019

Exactly what I needed to protect my laser tube. Pressure adjustable, tested with ohm meter and by function. Shut off pump, laser stopped firing. Great product and support!

Is my sensor somehow reversed?

Review by Tako on 3/2/2018

Is that possible? Mine seems to be a NC contact. It's closed when to pressure exists and the moment I turn on my pump and water starts flowing it closes! That's of course exactly the opposite of what it needs to be. Is it possible I somehow got a wrong one?


Review by LBaird on 11/29/2016

I recieved my LSR-H2OPRSNR but would like to know how many amps/volts I can use on it.

Acts like a Momtary switch

Review by Roy on 10/20/2016

Product is well made but final testing before stocking poor. If there were some inspection before stocking the problem would have been found. The switch acts like a momentary switch. at any setting of the dial or water pressure. Contact Lightobject and asked if I could open it up to repair and found that one of the terminals was loose. Tight as much as I could and then working fine. But have no faith in it.

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