// Catalogue

Flow Sensors: Hydraulic Flow Meters, Flow Transmitters and Flow Switches

Flow sensors measure how much fluid is moving, or confirm it’s moving at all, in oil, coolant and lube lines. TSA Hydraulics Engineering supplies meters and switches within the Sensors & Switches family of our Motors & Drives range, alongside Pressure Sensors, Temperature Sensors, Condition Monitoring, and Hoses, Pipes & Fittings.

Viscosity changes everything. A turbine meter that reads perfectly on water can be way off on cold oil, while a gear meter barely notices the difference. So the fluid and its temperature decide the sensor before the flow rate does. Tell us the fluid, range, and pressure, and we’ll match a genuine or equivalent sensor.

// Buying guide

Types of Flow Sensor

Gear (positive displacement) meters: count fixed volumes and stay accurate across a wide viscosity range. A strong choice for hydraulic oil.
Turbine meters: compact and fast, best with thin, clean fluids at a steady temperature.
Variable area meters: a float or spring loaded piston shows flow on a scale, often with a switch contact.
Paddle and vane flow switches: simple confirmation that water or coolant is flowing.
Thermal flow switches: no moving parts, ideal for confirming cooling water or lubricant flow.
Electromagnetic meters: for water and other conductive liquids only. They won’t read oil.

Where Flow Sensors Help

Checking pump wear: flow at full pressure drops as a pump wears inside.
Case drain monitoring: rising case drain flow is an early warning of pump or motor wear.
Cooling water: confirming water is reaching the heat exchanger before the oil overheats.
Lubrication lines: proving that bearings and gearboxes are getting oil.
Test benches: measuring flow alongside pressure to plot pump and valve performance.

Choosing a Flow Sensor

Name the fluid and its viscosity range, from cold start to full temperature.
Set the flow range, with normal flow near the middle of the scale.
Check the pressure rating, especially on high pressure hydraulic lines.
Decide on the output: pulse, 4 to 20 mA, a switch contact or a local display.
Check the pressure drop the sensor adds.
Match the port size and thread.

Installation Tips

Fit a filter upstream of gear and turbine meters, because dirt jams fine clearances.
Install in the direction of the arrow, and keep air out of the line.
Add isolation valves or a bypass so the sensor can be removed without a shutdown.
Leave straight pipe before turbine and paddle sensors if the maker asks for it.

Using Flow Data

Flow on its own tells you a lot, but paired with pressure and temperature it shows the real health of a system. Trending case drain flow or pump output over months lets you plan a pump change before it fails, instead of after.

Signs of a Faulty Flow Sensor

Readings that drop to zero while the machine is clearly running.
A gear meter that sticks or reads in bursts, often from dirt.
Readings that drift as the oil warms up.
A flow switch that never changes state.

Flow Sensors Specifications to Check

Sensor type and measuring principle
Flow range and turndown
Fluid and viscosity range
Maximum pressure and temperature
Output signal, switch point or display
Port size, thread and pressure drop

Why Buy From TSA Hydraulics Engineering

As a flow sensors supplier, we start with your fluid, viscosity and pressure, then match the sensor type, range and ports. You get clear prices in AUD, OEM or equivalent options, and help sourcing flow sensors replacement parts such as sensor heads, cables, displays and seal kits. We tell you upfront whether a sensor is genuine or an equivalent.

// FAQs