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- Sigma 910
- Sigma 911IS
- Sigma 920
- Sigma 930
- Sigma 940 IS
- Sigma 950 Opti-Flo
- Sigma 980
Sigma 910
Area Velocity Flow Meter
The Sigma 910AV measures average velocity directly without the need for time consuming flow profiling, significantly reducing the cost of installation and operation. With a compact 4 1/2 x 18" design, weighing less than 8 lbs (with battery), the 910AV is one of your best options for remote environments. This meter will log level and velocity data for more than 30 days without changing a battery, and its sealed design provides superior system protection against surcharge conditions.- Low-profile probe reduces maintenance and is detachable/interchangeable for ultimate flexibility.
- Easy installation with a small, 4½ in. diameter and no velocity calibration required. NEMA 6P sealed to withstand submergence and prolonged surcharge conditions.
- Advanced, ultrasonic on-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 910 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 for:
- Short Term Flow Studies
- Sanitary Sewer Evaluation Studies
Sigma 911 IS
Intrinsically Safe Portable 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.- 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.
- Short Term Flow Studies in Hazardous or Potentially Hazardous Areas
- Sanitary Sewer Evaluation Studies CSO Studies and Monitoring
Sigma 920
Area Velocity Flow Meter
The Sigma 920 Area Velocity Flow Meter can be used in portable or permanent applications and is available with up to two independent level/velocity channels. You can measure level and velocity in two channels or velocity in one and level in another. And, with Hach Sigma´s pager communication, you can be alerted to overflows, bypasses, or a change in the flow pattern. Choose from submerged pressure transducer/velocity sensor or American Sigma In-Pipe Ultrasonic Depth Sensor combined with a "wafer-thin" velocity sensor that provides greater accuracy in shallow flows. - Multiple sensors for redundancy, averaging and multiple pipe monitoring.
- Easy installation with fast setup and no velocity calibration required.
- Sampler pacing capabilities, ideal for CSO and storm water.
- Optional rainfall logging feature records and characterizes rain events, a true innovation in water monitoring.
- NEMA 6P sealed to withstand submergence and prolonged surcharge conditions.
- Low power draw creates an extended 90-day battery life.
- Advanced, ultrasonic one-MHz Doppler technology avoids signal dropouts and ensures high levels of accuracy in low-flow, full-pipe, or reversed-flow conditions, without the need for on-site calibration.
- A higher level of accuracy, since the Sigma 920 automatically corrects the effects of temperature on level measurement.
- Patented "Drawdown Correction" feature corrects the effects of velocity on accurate level measurement.
Ideal for:
- Short Term Flow Studies
- Sanitary Sewer Evaluation Studies
- CSO Studies and Monitoring
Sigma 930
Long-Term Area Velocity Flow Meter
The Sigma 930 Long-Term Area Velocity Flow Meter - our most advanced flow meter - supports three interchangeable sensors, long battery life, and increased data storage, and offers optional interfaces with samplers and modem capability.
The Sigma 930 Long-Term Area Velocity Flow Meter is designed for long-term/permanent flow studies with approximately 365-day battery life and a strong NEMA 6P PVC enclosure. Permanent collection system monitoring can now be done confidently, within an affordable budget.
- Multi-point and/or redundant monitoring with a single meter.
- Up to three level and velocity sensors.
- Low power draw creates an extended year-long battery life.
- Optional rainfall logging feature records and characterizes rain events, a true innovation in water monitoring.
- Optional internal modem automates data retrieval, paging and reporting.
- Optional sampler pacing capabilities, ideal for CSO and Stormwater.
- NEMA 6P sealed to withstand submergence and prolonged surcharge conditions.
- Advanced, ultrasonic one-MHz Doppler technology avoids signal dropouts and ensures high levels of accuracy in low-flow, full-pipe or reversed-flow conditions, without the need for on-site calibration.
- A higher level of accuracy, since the 930 automatically corrects the effects of temperature on level measurement.
- Patented drawdown correction feature corrects the effects of velocity on accurate level measurement. Multiple sensors for redundancy, averaging and multiple pipe monitoring.
Ideal for:
- Long-Term Flow Monitoring Sanitary
- Sewer Evaluation Studies
- CSO Studies and Monitoring
- NPDES Stormwater Compliance
- Permanent Collection System Monitoring
Sigma 940 IS
Intrinsically Safe Area Velocity Flow Meter
The Sigma 940 Intrinsically-Safe Flow Meter supports dual sensors, interfaces with samplers, has a long battery life, and offers increased data storage and optional modem capability.The Sigma 940 Flow Meter is the safest investment for your sewer and your budget. With the 940, remote monitoring becomes a way of life. Its rugged design, low-profile probes and long battery life significantly reduce site visits. Choose up to two area velocity sensors, or one area velocity and one level backup. Whether you're experiencing redundancy in a single pipe or level and velocity in separate pipes, you'll profit from new performance levels in a single meter.
Industry standard MODBUS ASCII protocol has been incorporated into the Sigma 940 Flow Meter. The implementation of the MODBUS protocol will allow your MMI, SCADA or DCS system to directly communicate with the 940 Flow Meter without the use (or additional cost) of a PLC. Now you can have real-time, read-only access to all available data channels in the 940 Flow Meter.
- CSA-NRTL/C DEMKO listed and certified for operation in Class I, Division I, Groups C & D hazardous locations.
- Multiple sensors for redundancy, averaging and multiple pipe monitoring.
- Telephone and pager alarms for quick notification of system changes.
- Low power draw, with a long, one-year battery life.
- NEMA 6P sealed to withstand submergence and prolonged surcharge conditions.
- Sampler pacing capabilities, to document the extent of overflow problems.
- Advanced, ultrasonic one-MHz Doppler technology avoids signal dropouts and ensures high levels of accuracy in low-flow, full-pipe or reversed-flow conditions, without the need for on-site calibration.
- A higher level of accuracy: the 940 automatically corrects the effects of temperature on level measurement.
- Patented Drawdown Correction feature corrects the effects of velocity on accurate level measurement.
Ideal for:
- Long Term Flow Monitoring in Hazardous or Potentially Hazardous Areas
- Sanitary Sewer Evaluation Studies
Sigma 950 Opti-Flo
Area Velocity Flow Meter
The Sigma 950 and 950 AV Series Flow and Water Quality Meter provide portable and/or permanent single-channel monitoring plus water quality testing, process control interface, and a digital display. The Sigma 950 and 950 AV Optiflow models offer maximum flexibility for multiple applications. Up to three different level sensor technologies and velocity are available in one meter.For applications requiring more than flow, the 950 optionally monitors rainfall, pH, temperature, ORP, dissolved oxygen and/or conductivity. In addition, the 950 has analog inputs for data-logging from other instruments, for example, total suspended solids monitors.
You can also control samplers, pumps, or other equipment based on flow or selected parameter(s) exceeding high/low set points with relay outputs.
Meters in the Sigma 950 Series are versatile to meet your needs - customize your meter to specific site conditions easily. The large LCD graphics display lets you quickly see the information you need quickly, on-site, in your choice of 10 languages, and without the inconvenience of outdated paper charts; you'll no longer need to replace pens, paper, or service mechanical recorders.
Industry standard SCADA MODBUS ASCII protocol is included in the Sigma 950 Flow Meter Series. 4-20 mA outputs are also available: this allows flexible integration with a SCADA system. You can have real-time, read-only access to all available data channels in the 950 Flow Meter.
- Keypad and large graphics display makes using laptops in the field optional. A single keystroke provides an instantaneous flow summary and review of all program settings.
- Three level measurement technologies available: ultrasonic, submerged, or Bubbler.
- Battery or AC powered.
- Water quality data helps identify upsets that may affect your plant. An OptiFlow model provides maximum flexibility with three different level technology choices plus velocity.
- Doppler area velocity flow measurement.
- Sampler pacing ability to document the extent of overflow problems.
- Optional rainfall logging to record and characterize rain events.
- Remote communications capability via modem or RS-232.
- Enough memory to log more than 18,000 data points-expandable to 116,000 data points or over one year of flow data at a 5-minute logging interval.
- Flash memory for software enhancements without replacing e-proms or returning meter to factory.
- Optional four user-assignable alarm relays.
- Optional two user-assignable 4-20 mA outputs, allowing the meter to be part of a current loop able to drive recorders, samplers, metering pumps, chlorinators, and other devices or SCADA integration.
- Rugged, environmentally sealed: the Sigma 950 is NEMA 4X-6 rated and can survive submersion and corrosive gases-even with the door open.
- Data can be downloaded in any of three ways:
- Palm-sized Data Transfer Unit (DTU);
- Built-in modem to transmit data over telephone lines;
- Direct RS-232 link to a PC utilizing data analysis software
Ideal for:
- Long Term or Permanent Flow Studies
- Sanitary Sewer Evaluation Studies
- CSO Studies and Monitoring
- NPDES Stormwater Compliance
- Industrial Compliance Monitoring Applications involving frequent moving of meter to different site conditions
Sigma 980
Permanent Flow Meter
The Sigma 980 Flow Meter provides the versatility needed to handle a wide range of applications and site conditions. It has been designed to use three different sensing technologies so that you can choose the most appropriate one for your specific flow situation. In addition, the flow meter can connect to a wide variety of optional peripheral devices such as 4-20 mA outputs, analog inputs, mechanical totalizer, rain gauge, sampler, pH sensor and modem that allow you to customize the 980 to your particular site needs.
The 980 Flow Meter also has several features designed to simplify installation, operation and maintenance. It has eight holes along the bottom of the case in order to provide access to power, sensor, control and communications wiring.
The large LCD graphics display lets you quickly see the information you need, on site without the inconvenience of outdated paper charts. Industry standard MODBUS ASCII protocol has been incorporated, which will allow your MMI, SCADA or DCS system to directly communicate with the 980 Flow Meter without the use (or additional cost) of a PLC.
Features / Benefits:
- Three Different Level/Flow Sensing Technologies: Non-contacting ultrasonic; submerged pressure;
- Doppler velocity.
- Advanced Monitoring: Measures flow, level, pH, temperature, rainfall, and more.
- Large, Easy-to-Read Graphics Display: Provides maximum amount of graphed or tabular data at a glance.
- Flexible Power Supply: Automatically regulates input voltage (100 to 230 VAC, 50/60 Hz).
- Data Logging: Minimum of 396 days of three channels of user-selected readings at 15-minute intervals. Up to 300 events.
- Numeric Keypad: Sealed-membrane switch keypad. Audio signal confirms keystroke has registered.
- Built-in Flow Equations: Simply select the primary device. Or use the Manning Equation. For custom applications, enter up to 99 head-versus-flow data points. You select the level and flow units.
- Seven External Analog Inputs: Consolidate 4-20 outputs from other monitoring equipment into a standard format.
- Simple Documentation: Generate charts, graphs, and reports with American Sigma´s software package.
- Alarm Relays: Four user-assignable, set-point and trouble alarms.
- Pacing: Will pace samplers or other equipment in proportion to flow.
- Water-Resistant Enclosure: Environmentally sealed NEMA 4X case for longer life and minimal service.
- Modbus® SCADA Communications: The Sigma 980 Permanent Flow Meter incorporates MODBUS Protocol for use in SCADA (Supervisory Control and Data Acquisition) systems.
- (MODBUS is a trademark of Scheider Automation, Inc.)
The 980 Flow Meter is ideal for:
- Influent Monitoring Effluent Monitoring
- WWTP Process Monitoring
- NPDES Stormwater Compliance
- CSO Monitoring
- Long Term/Permanent Flow Monitoring
Sigma's Patented Drawdown Correction & the Bernoulli Principle:
The Bernoulli Principle states that as the velocity of a fluid increases, its pressure decreases. The Bernoulli Principle simply describes the relationship between the velocity of a fluid and its pressure. If a measurement of the pressure of the moving fluid is taken at a point just forward of the front edge of the shape, and another measurement is taken at the apex, of the upper curved surface, one would notice that the pressure at the apex is lower than the pressure at the leading edge. It is this same principle that is responsible for the lift on an airplane wing. Level measurement using a submerged depth sensor is similarly affected by increases in fluid velocity.
1. As the velocity of water increases past the probe.
2. A drop in pressure (vacuum) is induced near the pressure sensor (level) port located at the sides of the probe.
3. This results in the lowering of the indicated level (or pressure) sensed at the port.
4. Sigma's patented "Drawdown Correction" software adjusts the level readings for this effect. Sigma's patented drawdown correction adjusts for these effects through software. The software correction algorithms are based on flow data collected during extensive laboratory and real life testing.
This testing resulted in US patent # US5691914:
Fluid flow measurement correcting system, and methods of constructing and utilizing the same. Abstract: "An apparatus for calculating fluid flow in a channel, comprising a probe member which detects fluid depth in the channel; a mechanism for measuring average fluid velocity in the channel; a mechanism for correcting the detected fluid depth based upon the measured average fluid velocity in order to account for drawdown; and a mechanism for calculating average flow rate based upon the average fluid velocity measurement and the corrected fluid depth value."
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