Standard 800 Series metering flow switches are calibrated with water at approximately 25 °C / 77 °F. The use of fluids other than water may affect the accuracy of measurement due to differences in viscosity. Proteus’ world-class calibration capability allows us to deliver instruments with specialized temperature- and fluid-specific calibration. Please contact Applications Support at or (650) 964-4163 for more information.

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(650) 964-4163

(650) 965-0304

For special orders and California reseller with a resale certificate, please call us directly to place your order.

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Phone: (650) 964-4163

Proteus offers free samples of standard Proteus-manufactured flow switches or flow meters for evaluation in new applications by prospective OEM customers.

To request a free sample, please send an e-mail describing your application to with “Free Sample” in the subject line. Be sure to include your name, the name of your company, the address to which the sample should be sent and your telephone number. You may also call Mark Malfatti or David Chiasson at (650) 964-4163.

Who is an OEM?


OEM customers are those who incorporate our product into their own product for commercial sale to end users. Usually, you will have a website or product data sheet showing a product that incorporates flow measurement.

WeldSaver™ products, Tofco flow products and Florite control units are not included in this offer. There is a limit of one free sample per customer. Proteus Industries retains the sole right to determine which companies are qualified OEMs for the purpose of this offer.

  • 800 Series Metering Flow Switch
  • 800 Series Flow Switch

800 Series

800 Series Metering Flow Switches

> Flow ranges from 0.2 to 227 LPM / 0.05 to 60 GPM
> Liquid temperatures from -40 to 140°C / -40 to 284°F
> Pressure to 1724 kPa / 250 psi
> Calibrated 0–5 VDC output
> Relay trip point – 16 preset settings
> Compact design
> 5-year warranty