--- product_id: 453882455 title: "1/2\" Water Flow Sensor Food-Grade Switch Hall Effect Flowmeter Fluid Meter Counter 1-30L/min (Pack of 2）" brand: "gredia" price: "NZ$188" currency: NZD in_stock: false url: https://www.desertcart.nz/products/453882455-1-2-water-flow-sensor-food-grade-switch-hall-effect store_origin: NZ region: New Zealand --- # Flow Rate: 1-30L/min Voltage: DC 5-24V Material: Food-Grade Plastic 1/2" Water Flow Sensor Food-Grade Switch Hall Effect Flowmeter Fluid Meter Counter 1-30L/min (Pack of 2） **Brand:** gredia **Price:** NZ$188 **Availability:** ❌ Out of Stock ## Summary > 💡 Flow into the Future with Precision! ## Quick Answers - **What is this?** 1/2" Water Flow Sensor Food-Grade Switch Hall Effect Flowmeter Fluid Meter Counter 1-30L/min (Pack of 2） by gredia - **How much does it cost?** NZ$188 with free shipping - **Is it available?** Currently out of stock - **Where can I buy it?** [www.desertcart.nz](https://www.desertcart.nz/products/453882455-1-2-water-flow-sensor-food-grade-switch-hall-effect) ## Best For - gredia enthusiasts ## Why This Product - Trusted gredia brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Pack of 2 for Value:** Get double the efficiency with two sensors, perfect for both personal and professional use. - • **Eco-Friendly Materials:** Crafted from food-grade plastic that meets ROHS standards, prioritizing safety and sustainability. - • **Versatile Compatibility:** Easily connects to G1/4 inch male threads, making it perfect for a variety of devices like coffee machines and water purifiers. - • **Robust Pressure Handling:** Designed to withstand water pressure up to 1.75Mpa, ensuring durability and reliability. - • **Precision Flow Measurement:** Experience accuracy with a flow rate of 1-30L/min, ensuring optimal performance in your applications. ## Overview The GREDIA 1/2" Water Flow Sensor is a high-performance Hall Effect flowmeter designed for a wide range of applications, including water heaters, coffee machines, and more. With a flow range of 1-30L/min and a robust construction from food-grade materials, this sensor ensures both accuracy and safety. Ideal for professionals seeking reliable fluid measurement solutions. ## Description Our products are fine made with nice materials and good workmanship, strict quality control, guarantee in after service. The flowmeter is light and handy, easy to install. The sealing ring make the connection firm, the sealing performance is good and the problem of water leakage is avoided. More details about the flow meter: F=（7.5*Q）±2%, Q=L/Min, error: ±2% Working range: 1-30L/min Working voltage: DC 5-24 V Water Pressure: ≤1.75Mpa Liquid temperature: 0-100℃ Maximum current consumption: 15 mA(DC 5V) Wire length: 15 cm Size: 62mm x 36mm x 36mm(L*W*H) Refer to the wiring: Red wire: VCC(+) Black wire: GND(-) Yellow wire: Signal output Package: 2 x G1/4 inch flowmeter Review: Working good for 2 months. - Working good for 2 months. Review: Using with a reef aquarium to control flow thru a UV sterilizer - I've adapted this Gredia GR-201 1/2" flow sensor paired with a Digiten Flow Meter to monitor flow rate thru a UV sterilizer. The sterilizer I have requires a flow at 37 GPH optimum and 60 GPH max to be effective eradicating protozoa. Out of the box the pairing of the meter and sensor was way off reporting 16 GPH while a had a gate valve nearly closed. So to calibrate it, the meter has a K-factor value that has to be adjusted to the sensor you pair it with. The default was a K-factor value of 1.98. I did a Google Bard search for what the sensors K-factor should be... 11.45. I set the meters K-factor to that. It was much closer but not accurate. I adjusted my valve until the meter was reading 1 GPH of flow. I set up a bucket to divert the water exiting the system into so I could measure the amount dispensed in a minute. I recorded .453 gal. with the K- 11.45. Now a little math, divide the current K- (11.45) by the flow it produced (0.453) while the valve restricted flow with the meter reading 1 GPM. The resulting new K-factor of 25.27 worked precisely. Well, as precise as using a large measuring cup to measure the amount of water dispensed. I re-ran the test, I got 1 gallon at the 1 minute mark, 3 gal at 3 minutes. The one annoying thing about the meter is the backlit display goes dark after 15 seconds. Annoying during the calibration when your hands are busy turning on/off a pump and a timer. But in actual use I'll only be using this to set the gate valve position and the backlighting won't so much be an issue. I hope this helps those trying to get a more accurate reading. ## Features - Connect to G1/4 inch male thread, hall effect, comes with 2 pieces - Flow range:1-30L/min, Water Pressure: ≤1.75Mpa - Working voltage: DC 5-24 V, F=（7.5*Q）±2%, Q=L/Min - Material: food grade plastic, all raw materials conform to the ROHS test standard - Wide application: It is mainly used in water heater, coffee machine, water purifier, drinking fountain, beverage machine, campus smart card equipment, etc. ## Technical Specifications | Specification | Value | |---------------|-------| | Brand | GREDIA | | Manufacturer | GREDIA | | Country of Origin | USA | | Model number | GR-201P2 | | Number of Memory Sticks | 2 | | Item Weight | 100 g | | Package Dimensions | 18.11 x 11.71 x 3.51 cm; 100 g | | Item model number | GR-201P2 | | Are batteries included? | No | ## Images ![1/2" Water Flow Sensor Food-Grade Switch Hall Effect Flowmeter Fluid Meter Counter 1-30L/min (Pack of 2） - Image 1](https://m.media-amazon.com/images/I/61nLiOnDsJL.jpg) ![1/2" Water Flow Sensor Food-Grade Switch Hall Effect Flowmeter Fluid Meter Counter 1-30L/min (Pack of 2） - Image 2](https://m.media-amazon.com/images/I/61pUNNCWDAL.jpg) ![1/2" Water Flow Sensor Food-Grade Switch Hall Effect Flowmeter Fluid Meter Counter 1-30L/min (Pack of 2） - Image 3](https://m.media-amazon.com/images/I/61D8ujyEenL.jpg) ![1/2" Water Flow Sensor Food-Grade Switch Hall Effect Flowmeter Fluid Meter Counter 1-30L/min (Pack of 2） - Image 4](https://m.media-amazon.com/images/I/61fM7z5z0YL.jpg) ![1/2" Water Flow Sensor Food-Grade Switch Hall Effect Flowmeter Fluid Meter Counter 1-30L/min (Pack of 2） - Image 5](https://m.media-amazon.com/images/I/5142HDOWNBL.jpg) ## Available Options This product comes in different **Size** options. ## Questions & Answers **Q: If the output signal is a pulse, what is the pulse rate per liter and duration per pulse?** A: The current image shows an "F" number of 7, which means 7Hz per liter/min, so 7 pulses per second indicates a flow rate of 1 liter/minute, hence 7 * 60 seconds/minute = 420 pulses per liter (per minute). I have no idea what the duration would be. **Q: Does it prevent back flow or what happens if water does try to go in wrong direction?** A: It does not have any backflow prevention. It is a little water wheel inside a pipe which has magnets in the vanes of the water wheel. The unit simply counts magnetic pulses as the wheel is moved by the water flow. It would probably register water flow either way but would only be accurate in the forward flow direction. Any domestic water system should have backflow preventers in place to keep drinking water contamination from occuring. **Q: Are the threads npt, bspt or bspp? please understand this is basic info should always be provided without having to specifically ask. thanks.** A: Hello, thank you for your inquiry. It's BSPT. **Q: If the flow rate is less than 1L/minute, will it not not show any pulses? I'm interested in using this to detect leaks and 1L/min is a lot of water.** A: I don't know about 1L/min, but I have tried pumping liquid through one using a dosing pump and nothing registered. The water wheel will have some resistance, so a very slow flow might not register. ## Frequently Bought Together - GREDIA 1/2" Water Flow Sensor Food-Grade Switch Hall Effect Flowmeter Fluid Meter Counter 1-30L/min (Pack of 2） - Ximimark 2Pcs 1/2" Thread Plastic Electric Solenoid Valve Water Inlet Flow Switch Magnetic Water Air Normally Closed Tools DC 12V N/C 0.02 to 0.8mpa - GREDIA 1/2" DC 12V Solenoid Valve N/C Normally Closed Water Inlet Flow Switch --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.nz/products/453882455-1-2-water-flow-sensor-food-grade-switch-hall-effect](https://www.desertcart.nz/products/453882455-1-2-water-flow-sensor-food-grade-switch-hall-effect) --- *Product available on Desertcart New Zealand* *Store origin: NZ* *Last updated: 2026-06-03*