


Sage Metering Model 51 Natural Gas SubMeter
$3,500.00
Thermal Mass Natural Gas Flow Sub-Meter
Revolutionize Your Natural Gas Monitoring
Introducing the Emergent Metering Natural Gas Series Meter– the ultimate flow meter for precise natural gas and air flow measurement in commercial and institutional buildings. Whether you’re managing a sprawling university campus, a busy hospital, or a complex office building, our thermal mass flow meter delivers unparalleled accuracy and efficiency.
Flow Meter Key Features:
Direct Mass Flow Measurement: No additional temperature or pressure transmitters required
High Accuracy: Within 1% of actual value, NIST calibrated with natural gas or air
Impressive Turndown: 100:1 ratio with resolution up to 1000:1
Low-End Sensitivity: Measures as low as 5 SFPM
Negligible Pressure Drop: Maintains energy efficiency
No Moving Parts: Ensures long-term reliability and accuracy
Perfect for HVAC Applications:
Inline or insertion-style options
Available with flow conditioner (minimizes pipe run requirements)
Easy installation and maintenance
High rangeability for both low- and high-flow scenarios
Facilitates LEED credits
Compact design (4-1/8″ dia. x 4-1/4″ deep)
CI D2 hazardous location rating
Advanced Communication:
BACnet communication standard (Modbus RTU optional)
Isolated 4-20 mA output for flow rate
Pulsed output for totalized flow
Optional dry contact relay module
Ideal for:
Mechanical contractors
Performance contractors
Campuses and universities
Energy service companies (ESCOs)
With the Emergent Metering natural gas meter, you can maximize your boiler system’s efficiency and reduce energy consumption. Experience the power of precise natural gas monitoring today!
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Product Details
Sage Model 51 HVAC Series of Thermal Mass Flow Meters measures Natural Gas flow rate and consumption in commercial and municipal buildings, as well as college and university campuses, government facilities, hospitals, shopping centers and office buildings and complexes.
The HVAC Industry (Heating, Ventilation and Air Conditioning) provides processes, products, systems, and services that are aimed at heating, ventilating, and air conditioning buildings and facilities while maintaining thermal comfort, acceptable indoor air quality, and reasonable installation, operation, maintenance, and energy. Thus the need for accurate natural gas monitoring is critical, and the cost-effective Model 51 Thermal Mass
Flow Meter is the ideal measurement solution. The HVAC Series is available as an In-Line or Insertion style meter and provides a 4-20 mA analog output proportional to the NG flow rate, as well as pulsed outputs of totalized flow, and includes an easy to read display of flow rate, total, and temperature. In addition, BACnet communication is provided (or optional Modbus RTU) for communicating with energy dash-boards or other software Masters.
All Model 51 HVAC Thermal Mass Flow Meters are temperature-compensated and pressure insensitive, and are configured to provide a 100 to 1 turndown of natural gas with a Full Scale flow rate based on the pipe size specified. Over 165 samples are taken in the Sage NIST calibration facility to guarantee 1% of reading accuracy
Sage Model 51 HVAC Series | Natural Gas Thermal Mass Flow Meter
Sage Model 51 HVAC Series thermal mass flow meter for natural gas: ±1% of reading, 100:1 turndown, 24 VDC, OLED display, isolated 4–20 mA, pulse total, BACnet or Modbus RTU.
The Sage Model 51 HVAC Series Thermal Mass Flow Meter is designed to measure natural gas flow rate and total consumption in commercial and municipal buildings, as well as:
- College and university campuses
- Government facilities
- Hospitals
- Shopping centers
- Office buildings and complexes
Accurate natural gas monitoring is critical in HVAC applications, and the Sage Model 51 provides a cost-effective and highly accurate measurement solution.
Key Features
The Sage Model 51 HVAC Series is available in two configurations:
In-Line style
Insertion style
It provides:
- 4–20 mA analog output proportional to natural gas flow rate
- Pulsed outputs for totalized flow
- Local display showing:
- Flow rate
- Totalized flow
- Temperature
- It also includes BACnet communications as standard, with optional Modbus RTU for integration with energy dashboards and other master systems.
Why Thermal Mass Flow Metering?
Thermal mass flow meters provide several major advantages, including:
- Direct mass flow measurement
- No need for separate temperature or pressure transmitters
- High accuracy and repeatability
- Turndown ratio of 100:1
- Resolution up to 1000:1
- Low-end sensitivity
- Measures as low as 5 SFPM
- Example: 7 SCFH in a 2” pipe
- Negligible pressure drop
- Will not impede flow or waste energy
- No moving parts
- Eliminates costly bearing replacements
- Prevents undetected accuracy shifts
Flow Meter Advantages (HVAC Natural Gas)
The Sage Model 51 HVAC Series provides:
- Mass flow measurement for natural gas
- In-line or insertion meter options
- Easy installation
- High rangeability for both low and high flows
- High reliability
- Supports energy consumption reduction efforts
- Can help facilitate LEED credits
Compact enclosure size:
- 4-1/8” diameter x 4-1/4” deep
- BACnet communications (standard) or optional Modbus RTU
- Isolated 4–20 mA output for flow rate
- Pulsed output for totalized flow
- Rugged, user-friendly packaging
- Easy terminal access
- Built-in flow conditioning for in-line meters (½” and up)
- Optional dry contact relay module (DCR-DC)
Accuracy & Performance Specifications
- Standard performance specifications include:
- Accuracy: ±1% of reading
- Repeatability: 0.2%
- Turndown: 100:1
- Resolution: up to 1000:1
- For natural gas meters:
- 1% of reading applies above 500 SFPM (velocity units)
- The electronics include:
- 4–20 mA output proportional to mass flow rate
- Pulsed outputs for totalized flow
- BACnet communications (standard)
- Optional Modbus communications
Display, Enclosure & Wiring Design
- The Model 51 HVAC Series includes:
- Bright, high contrast, photo-emissive OLED display
Displays:
Flow rate
Totalized flow
Temperature
The meter includes a dual-sided NEMA 4 enclosure with:
Lightweight, robust design
A rear compartment separated from electronics
Large, well-marked terminals for easy wiring
Power Requirements
The Sage Model 51 HVAC Series is powered by:
- 24 VDC
- Power dissipation under 2.5 watts
- (Example: under 100 mA at 24 VDC)
Configuration & Ordering Notes
To specify a unit:
- Select the pipe size
- Choose SCFM units
- Meter is pre-configured for the specified pipe size
- Totalized flow pulse output is pre-configured for the specified pipe size
- Sage recommends contacting them for typical flow rates for your pipe.
Certifications & Approvals
The Sage Model 51 HVAC Series is:
- CE approved
- CSA approved
- UL approved for Hazardous Service
- model-51-hvac
Available Styles
- Model 51 In-Line
- The in-line flow element consists of:
- 316 Stainless Steel Schedule 40 flow bodies
Sizes from:
- ¼” x 6” long
- Up to 4” x 12” long
Model 51 Insertion
- The insertion flow element consists of:
- ½” OD probe
- Probe lengths up to 18”
- Typically 15” long
- Suitable for insertion into the center of a process pipe
In-Line Meter Dimensions
Pipe size x flow body length:
- ¼” x 6” → 1-1/4” x 10”
- 3/8” x 6” → 1-1/2” x 12”
- ½” x 7” → 2” x 12”
- ¾” x 7” → 2-1/2” x 12”
- 1” x 8” → 3” x 12”
- 4” x 12”
Potential buyers and users include:
- Mechanical contractors
- Performance contractors
- Campuses and universities
- Energy service companies (ESCOs)
