Thermal Dispersion Flow Transmitter has no moving parts.

Press Release Summary:

Series TDT thermal dispersion flow transmitter, used for metering of all fluid media, has adjustable insertion mounting for pipe sizes of 1-24 in., while extensions allow use with up to 75 in. dia pipes. Unit contains PT resistor that measures media temperature, and one that is heated by attached heating resistor. Flow of media cools heated resistor proportional to speed of flow, resulting in linear output signal proportional to flow speed. Unit is available in flow ranges up to 0-12.47 fps.

Original Press Release:

Series TDT Thermal Dispersion Flow Transmitter

The W.E Anderson Division of Dwyer Instruments, Inc., the preferred source for your complete range of practical and affordable instrumentation, is announcing the release of its new and innovative SERIES TDT THERMAL DISPERSION FLOW TRANSMITTER.

Series TDT is an excellent alternative to turbine and paddlewheel insertion flow meters, with the ability to deliver high accuracy over a wide range of pipe sizes. These units have the same insertion mounting into a 1-1/2½ NPT but have no moving parts to wear, break or clog. The TDT Dispersion Transmitter measures very low flow rates due to the applied calorimetric principle and can be used for the metering of all fluid media, such as: water, oil, aggressive media, paste, glue, sludge, grease, etc. Due to the adjustable insertion mounting, one model is suitable for pipe sizes of 1½ to 24½, and with available extensions, it can be used for pipes sized up to 75½ in diameter. Series TDT is also available in titanium, as well as an optional temperature output, broadening the applications usage.

The Series TDT operates with the use of a sensor head that contains two PT-resistors. One of these measures the temperature of the media, while the other is heated by an attached heating resistor. The temperature difference between the two PT-resistors is predetermined and a control circuit keeps this temperature difference constant. The flow of the media cools the heated PT-resistor proportional to the speed of the flow, which results in a linear output signal proportional to the flow speed.

Available flow range options include: 0 to 1.64 ft/s (0 to 0.5 m/s), 0 to 3.28 ft/s (0 to 1 m/s), 0 to 6.56 ft/s (0 to 2 m/s), 0 to 9.84 ft/s (0 to 3 m/s), and 0 to 12.47 ft/s (0 to 3.8 m/s).

Complete details are available on our website @

Dwyer Instruments, Inc.

P.O. Box 373

Michigan City, IN 46361

Phone: (800) 872-9141 or (219) 879-8000

Fax: (219) 872-9057

Internet address:


More from Software

All Topics

COVID-19 Response Suppliers COVID-19 Response:
Can Your Company Help Provide Critical Supplies?

We are using the power of our platform to aid in the mass shortage of critical supplies. If your company can help provide supplies, capabilities, or materials for products such as N-95 Masks and Tyvek SuitsPlease let us know.

COVID-19 Response Suppliers