Industrial flow meter selection is more complex than municipal or irrigation applications. Process fluid compatibility, pressure and temperature conditions, hygienic requirements, hazardous area classifications, communication outputs, and total cost of ownership all play a role.
The first question in any industrial flow meter selection is: what are you measuring? The answer drives most of the subsequent decisions.
Electromagnetic (mag) flow meters are the default choice.
Mag meters work for any conductive liquid with conductivity above 5 µS/cm.
Mag meters don't work for hydrocarbons, oils, or pure water; ultrasonic or Coriolis meters instead.
Mag meters can handle slurries with appropriate liner and electrode selection.
Food and beverage or pharmaceutical applications require hygienic mag meters with smooth bore liners and CIP/SIP-compatible designs.
As with any flow meter application, sizing is based on flow velocity through the pipe, not simply the pipe diameter. You'll need to confirm the pipe internal diameter, minimum and maximum flow rates, the normal operating flow rate where accuracy matters most, and whether reverse flow is a possibility. Getting the sizing right is essential: an oversized meter operating at low velocities may lose accuracy, while an undersized meter creates excessive pressure drop and velocity-related wear.
Confirm the meter's pressure rating exceeds your maximum operating pressure with an appropriate safety margin. Process temperature affects liner material selection: standard PTFE or rubber liners suit most water and mild chemical applications, while high-temperature applications require appropriate liner materials.
Process control and billing: ±0.5% or better. Batch control: ±0.2% or better for critical applications. General process monitoring: ±1–2%. Effluent and waste monitoring: ±2–5% depending on consent requirements.
4–20mA, universally compatible. HART, remote diagnostics over existing 4–20mA wiring. MODBUS RTU/TCP, widely used in industrial SCADA. Profibus DP / Profinet, for Siemens and major PLC platforms. Confirming the required protocol before specifying a meter avoids integration issues.
If your meter is installed in a Zone 1, Zone 2, Division 1, or Division 2 classified area, the meter and transmitter must be certified for that classification. Confirm the area classification and required certification before specifying a meter.
Over a 10-year period, maintenance, verification, spare parts, and replacement costs all add up, so keeping on top of regular maintenance will be the difference between a meter going in a skip or staying in service for another 10 years. No moving parts (mag, ultrasonic) significantly reduce maintenance costs versus moving parts designs, but it's still not set and forget. The main step is to get the right meter installed that is fit for purpose.
Yes, provided the meter is designed for hygienic applications, smooth bore liners (PTFE), flush-mounted electrodes, and hygienic process connections (Tri-Clamp, DIN 11851).
If the installed meter is measuring water from a consented bore supply, or trade waste heading out the door, then yes, verifications will need to align with your consent or council conditions. Process flow meters do not require verification unless this is specified internally as a requirement. Calibration may be required if the measured fluid or product falls under Weights and Measures regulations, such as selling a known volume of product to a company or individual.
Yes, Zone 1/Zone 2 and Division 1/Division 2 classified areas. Confirm your area classification and required certification when enquiring.
A hygienic mag meter has a smooth bore, flush-mounted electrodes, hygienic process connections, and a surface finish suitable for CIP/SIP cleaning, required for food and beverage and pharmaceutical applications.
Canterbury-based flow meter specialists. Blue Tick accredited. IANZ-calibrated equipment.
Get in touchWe supply flow meters for industrial process applications across New Zealand and back it up with Canterbury-based installation, verification, and service support.