Current position > Product detail
『Hunter Wireless Hc Flow Meter: Troubleshooting Signal Loss Failures in Underground Water Systems』Related information(flow rotameter|digital flow meter|balo meter|hydraulic flow meter|volumetric meter|positive displacement meter|pitot tube flow meter|displacement meter|cfm meter|variable area flow meter|inline flow meter|differential pressure flow meter|calibrated flow meter|velocity meter|paddle wheel flow meter|oval gear flow meter|anemometer hvac|multiphase flow meter|doppler flow meter|thorpe tube flowmeter|heat flow meter)
Hunter Wireless HC Flow Meter Signal Loss: Troubleshooting for Underground Water Systems
Quick Answer: Signal loss in a Hunter Wireless HC flow meter installed underground usually comes from a low battery, water ingress at the antenna connector, or a buried antenna inside a concrete vault. Check the supply voltage and antenna routing first. If the signal still fails, switch to a wired flow meter with 4-20 mA HART or Modbus output.
Underground water systems in Australia, Southeast Asia, and the Middle East use wireless flow meters to avoid long cable runs. The Hunter Wireless HC flow meter works well in open air but underground vaults create a different RF environment. Wet soil, concrete lids, and metal access covers attenuate the signal more than most users expect.
We have seen customer sites in Vietnam where a Hunter Wireless HC flow meter worked perfectly during dry season and then lost signal after heavy rain. The cause was not the meter electronics. Water had entered the antenna junction box and changed the impedance at the connector.
Step 1: Check Battery Voltage and Power Connections
Start at the flow meter body. Open the transmitter housing and measure the battery voltage with a multimeter. Many wireless flow meters start behaving erratically when the battery drops below 3.0 V DC. A fully charged battery pack usually reads 3.6 V DC or higher. Check for corrosion on the terminals. In a pump station in Queensland we found green deposits on the power connector causing intermittent supply to the RF module.
Step 2: Inspect the Antenna and Cable Routing
Here is the thing, many users mount the antenna inside a metal vault or below a cast iron lid. That setup blocks the RF link before the meter has a chance to transmit. Never bury the antenna below grade. The antenna must sit above ground or inside a fiberglass enclosure with a non metallic lid. A concrete or cast iron vault lid blocks most signals. If you must put the antenna inside a vault, use a remote antenna extension no longer than 10 m. For 2.4 GHz systems the cable loss can be high. For 433 MHz or 900 MHz systems the cable loss is lower but still significant. Keep the antenna vertical and at least 300 mm away from metal pipes and steel brackets.
Step 3: Open Junction Boxes and Check for Water Ingress
Underground water systems always produce condensation. Even IP67 cable glands age. Open the antenna connector, battery compartment, and any junction box. Look for white powder, green corrosion, or water droplets. Dry the contacts and apply a small amount of dielectric grease. Most engineers skip this part when the meter is buried and the junction box is hard to reach. In one case a contractor in Saudi Arabia found the antenna connector filled with sand after a flash flood. The meter still measured flow locally but had no wireless link.
Step 4: Confirm Receiver Placement and RF Path
The receiver for a Hunter Wireless HC flow meter must have a clear line of sight if possible. Trees, earth berms, and metal equipment rooms reduce the range. In practice, a 2.4 GHz radio inside a wet concrete vault may only reach 30 to 60 m. A 900 MHz radio may reach 100 to 150 m under the same conditions. Move the receiver to a higher point or install a small pole mounted antenna. Test the RSSI value
_600x400.jpg)
Step 5: Replace the Wireless Transmitter or Switch to Wired Output
If the voltage is correct and the antenna system is dry, the wireless module may have failed. Order a replacement transmitter for the Hunter Wireless HC flow meter only if the meter body and sensor are still in good condition. If the housing has cracked or the battery terminals are heavily oxidized, a full replacement often costs less than repeated field repairs.
Recommended Replacement Flow Meters for Underground Water Systems
Silver Automation Instruments supplies battery powered electromagnetic flow meters for underground water lines from DN15 to DN2000. These meters provide wired outputs such as 4-20 mA HART, RS485 Modbus, pulse, and optional GPRS or LoRaWAN. The sensor can be rated IP68 for continuous submersion. This removes the RF path problem entirely because the signal travels through a cable or a cellular network.
For a DN100 underground line at 10 bar and 25 °C with a flow range of 5 to 120 m³/h, a Silver Instruments battery powered electromagnetic flow meter with IP68 sensor and RS485 Modbus output fits the existing pipe spool. For larger lines up to DN2000, we configure the same transmitter with remote or compact design.
We have supplied 12 battery powered electromagnetic flow meters to a water utility in Vietnam that had repeated signal loss on wireless units in below grade concrete vaults. The replacement meters used RS485 Modbus to a local RTU and GPRS to the central SCADA. Data availability went from about 80 percent to above 99 percent after the change.
FAQ: Hunter Wireless HC Flow Meter Signal Loss
Why does my Hunter Wireless HC flow meter lose signal only after rain?
Rain increases soil moisture and water can enter enclosures. Wet soil absorbs RF energy. Check seals and use a cable drip loop to direct water away from connectors.
Can I extend the antenna cable to bring the signal above ground?
Yes, but keep the extension short. For a 900 MHz system, a 10 m cable may lose 3 to 5 dB. For 2.4 GHz, the same cable can lose 8 dB or more. Use a remote antenna kit with factory connectors.
How do I know if the transmitter is dead or just losing RF signal?
Check the local display and pulse output first. If the flow rate updates locally but the receiver shows no data, the RF link is the problem. If the display is blank, check the battery and power wiring.
What wired output can replace the Hunter Wireless HC flow meter signal path?
A 4-20 mA HART signal works over standard twisted pair cable up to 1000 m. RS485 Modbus works up to 1200 m. For remote sites without cable ducts, a battery powered meter with GPRS or LoRaWAN sends data directly to a cloud platform.
What information should I prepare before requesting a replacement quote?
Send us your pipe size (DN), pressure (bar), temperature (°C), flow range in m³/h, and required output signal. Our engineers will propose a meter that fits the existing pipe and SCADA system.
Contact Silver Automation Instruments for technical selection. Tel: +86-25-68650347. Whatsapp: +86-25-52155837. WeChat: +86 15365082610. Email your parameters to our website flow-meter.com.au.