Sigma Model 911 Portable System
Sigma Model 911 Intrinsically Safe Area Velocity Flow Meter
With quick installation and minimum maintenance, the Sigma 911 Portable Area Velocity Flow Meters are ideal for short-term flow studies in hazardous or potentially hazardous environments. American Sigma´s advanced Doppler technology is accurate, even in low-flow, full-pipe, and reversed-flow conditions. There is no need for profiling to establish accurate average velocity. The Sigma 911 accuracy is further enhanced by a proprietary technology that corrects for the effects of temperature and velocity on level measurement.
System Benefits Include:
- CSA-NRTL/C certified for operation in Class 1, Division 1, Groups C & D hazardous locations, DEMKO listed.
- Low profile, non-fouling probe reduces your need for maintenance and is detachable/interchangeable for ultimate flexibility.
- Easy installation with a slender 6.5" in. diameter and no profiling required. NEMA 6P sealed to withstand submergence and prolonged surcharge conditions.
- Advanced, ultrasonic one-MHz Doppler technology avoids signal dropouts and ensures, without the need for on-site calibration, high levels of accuracy in low-flow, full-pipe, or reversed-flow conditions.
- A higher level of accuracy, since the Sigma 911 Portable Area Velocity Flow Meter automatically corrects the effects of temperature on level measurement.
- Patented "Drawdown Correction" feature corrects the effects of velocity on accurate level measurement.
Ideal Applications include:
- Short Term Flow Studies in Hazardous or Potentially Hazardous Areas
- Sanitary Sewer Evaluation Studies
- CSO Studies and Monitoring
Sigma Model 911 Data Sheet
Sensor
Submerged Area/Velocity
Compatible Software

