Company Profile

Field Mag Flow Meter 3000: Specifications for Agricultural Irrigation Systems

Quick Answer: The Field Mag Flow Meter 3000 measures irrigation water from DN50 up to DN600 with ±0.5 % accuracy and zero moving parts. It handles raw river water with silt, uses a polypropylene or hard rubber liner, and outputs 4-20 mA, pulse, or RS485 Modbus. Power options include 24 V DC, 220 V AC, or a solar panel kit for remote fields.

Why Irrigation Engineers Pick This Meter

Irrigation water is rarely clean. Pumps pull in sand, organic matter, and fine silt from boreholes and canals. A turbine meter clogs. An ultrasonic meter loses signal when the pipe is not full. The Field Mag 3000 has no obstructions inside the measuring tube. That means no filter is needed upstream. A farmer in the Mekong Delta told us he cleans his pump strainer monthly but has never opened the mag meter in three seasons. That is the kind of reliability a schedule-driven irrigation system demands.

The meter body comes in carbon steel with a welded flange connection. Liner choices are polypropylene for water up to 60 °C or hard rubber for higher abrasion. Electrodes are 316L stainless steel as standard. For saline groundwater or blended fertilizer water we fit Hastelloy C electrodes. We learned this from a date palm farm in Saudi Arabia where EC values went above 4 000 µS/cm. The standard electrode started drifting. Hastelloy solved it permanently.

Specifications That Matter for Agriculture

Pipe sizes range from DN15 for drip irrigation laterals to DN600 for main canal feeds. The flow velocity range is 0.1 m/s to 10 m/s. Most open-channel irrigation moves around 0.5 to 2 m/s so the meter stays well within its linear range. Accuracy is ±0.5 % of reading from 0.5 m/s upward. Below that it dips to ±0.2 % of full scale. Repeatability is 0.15 %. These numbers come straight from our calibration bench in Nanjing, traceable to a UKAS-accredited rig.

Output signals include 4-20 mA with HART, isolated pulse, and RS485 talking Modbus RTU. The converter housing is IP67. On request we supply a remote-mounted display that sits at eye level while the sensor stays buried in a valve pit. The display shows instant flow rate in m³/h or L/s, totalized volume, and diagnostic codes. One screen walkthrough and a farm technician can change pipe diameter or set the pulse weight for the dosing pump.

Power supply is flexible. The standard version runs on 24 V DC or 220 V AC. Where grid power is missing, like a sugarcane block in Western Australia or a greenhouse cluster in Kenya, we ship a 12 V / 24 V battery kit with a 30 W solar panel and a charge controller. The meter consumes 4 W maximum so a 100 Ah battery gives more than 200 hours of backup. Many customers pair it with a GPRS logger that pushes data to a cloud dashboard every 15 minutes.

Installation Notes from Customer Sites

Straight pipe requirements are 5D upstream and 2D downstream. A control valve should always be placed after the meter. Because the Field Mag 3000 needs a full pipe at all times, we recommend mounting the sensor in a low point of the line or using a siphon loop. A greenhouse operator in Spain once mounted the meter on a 2 % slope and got intermittent empty-pipe alarms. We moved the meter to the pump discharge header and the problem disappeared. Small field adjustments like this save a lot of commissioning hours.

Grounding is critical when the pipe is HDPE or PVC. The unit ships with a grounding ring kit. We have seen customers skip this step, then complain about fluctuating readings. With plastic pipe, fit the grounding rings on both flanges and link to a local earth rod. In conductive pipe like carbon steel or ductile iron the built-in ground electrode is enough.

Typical Application: A Citrus Orchard in Chile

A citrus grower near Ovalle upgraded from an old mechanical propeller meter to six Fi