About Us

Who are we?

We are an Australian-owned and operated company established in 1928, providing high-quality industrial instrumentation and engineering teaching equipment.

On the 12th January 1928, the roots of Duff and Macintosh Pty Ltd was formed. Originally named Crossle, Scott & Duff Brothers Limited, the company changed its name to Duff and Macintosh Pty Ltd when Donald Urquart Macintosh joined the company in the 1930s.

Donald Macintosh was William Vere Hobart (Bill) Duff’s brother in law.

Though Duff and Macintosh was officially handed to Mr Paul Orban in 1976, Mr Macintosh continued to work with the company and made regular appearances for a further 15 years.

Today, as in 1928, the company diligently maintains its reputation in the process instrumentation market, by supplying reliable equipment from reliable suppliers.

In the last few years, Duff and Macintosh Pty Ltd embraced new suppliers in the field of training and demonstration apparatus for tertiary education institutions and have successfully expanded sales into New Zealand.

Our range is diverse – a heritage from the age of our company and our efforts to succeed in other areas of business. Our oldest relationship to a supplier is nearly 60 years, with our oldest customer relationships exceeding 70 years!

We strive to make our customers happy. Quality and service are of utmost importance to Duff and Macintosh Pty Ltd, as only satisfied customers will return.

We thank you for visiting our website, and would welcome your enquiry.


What do we offer?

Flow – Electronic & Mechanical

  • Acrylic Bodied Flow Meters
  • Glass Tube Flow Meters
  • Metal Tube Flow Meters
  • Flow Transmitters
  • “Bouncing” Ball Flow Indicators
  • “Spinner” Flow Indicators
  • Brass & S/S Bodied Meters
  • Custom-Scaled Flowmeters
  • Digital Flow Meters
  • Digital Mass Flow Meters
  • Digital Mass Flow Controllers
  • Digital Volumetric Flow Meters
  • Digital Volumetric Controllers
  • Flow Switches & Alarms
  • Sight Flow Indicators

Level Transmitters & Switches

  • Level Transmitters
  • Level Switches: avail. in Polyprop., Kynar or Acetal

O.E.M. Transducers & Switches

  • Pressure Transducers
  • Level Sensors & Transmitters
  • Level Switches In PP, Kynar & Acetal
  • Force Transducers

Pressure – Sensing & Control

  • “OEM” Pressure Transducers
  • Plastic-Bodied Pressure Transducers
  • Stainless Pressure Transducers
  • Stainless Pressure Transmitters
  • Customised Pressure Sensors
  • Pressure Regulators
  • BackPressure Regulators
  • Electronic Pressure Regulators
  • Electronic Back Pressure Regulators

Process Gas Sampling

  • High Vapor Pressure Samplers
  • Liquefied Gases Sampler
  • Closed Loop Sampler
  • Manual Gas Concentration Sampler

Boiler Water/Steam/Sampling

  • Sample Coolers and Sequencers
  • Sample Panels (Wet Racks)
  • Sample Pressure Reduction
  • Thermal Shut-Off Valves
  • Degassed Cation Conductivity
  • Corrosion Products Samplers
  • Cooling Water Isolation Skids
  • Resin Columns
  • Sample Sequencers (Analyser Sharing)
  • Automated Sample Panels

Flameproof & Ex Instrumentation

  • Flow Switches
  • Level Switches
  • PressureSwitches
  • Vacuum Switches
  • Differential Pressure Switches
  • Pressure Transmitters
  • TemperatureTransmitters


  • Explosion Relief Valves
  • Transformer Valves
  • Flow Control Valves
  • Pressure Control Valves
  • High Pressure Sample Valves
  • Back Pressure Relief Valves

Education & Training Apparatus (Secondary Through To Post Graduate)

  • Aerodynamics
  • Automotive Electronics / Engineering
  • Biomedical Equipment
  • Consumer Electronics
  • Control Engineering & Sensors
  • Ecology
  • Electrical Engineering / Machines
  • Electrical Power
  • Electronics
  • Experimental Chemistry
  • Fluid Mechanics
  • Food Processing Technology
  • Industrial Chemistry
  • Industrial Process Control
  • Maritime Training Software
  • Materials Testing
  • Mechatronics
  • Robotics
  • Structures
  • Technology & Science / Principles
  • Telecommunications / Telematics
  • Theory of Machines
  • Thermodynamics
  • Renewable Energies