GM868 Ultrasonic Gas Flow Meter

  • Choice Of Meters Single or dual channel meters available capable of measuring all conductive gases
  • Extremely Low Maintenance Has no moving parts, no parts to collect debris and does not require lubrication or routine maintenance
  • Wide Pipe Size Range Capacity to measure pipe ranges from 1 inch to 120 inches
Product Options


The Panametrics GM868 is a multi purpose gas flow meter. The GM868 flow meter is suitable for measuring the flow of most gases including fuel gases, waste gases, stack gases and others. It is a complete ultrasonic flow metering system. The GM868 uses transit time technology to determine flow rates. It can do the job of several conventional meters, due to its wide range of measurement velocities and pipe sizes. The GM868 can measure the flow in pipes ranging from 1 inch to 120 inches in diameter (2.5cm to 3m) and also velocities ranging from 0.1 to 150ft/s. These velocities can be measured in either direction and in steady or pulsating flow.

A two channel gas flow meter can also be chosen to provide maximum accuracy by measuring along two paths in the same channel. The dual channel instrument can also be used to either measure the flow in two separate pipes or even at two seperate points on the same pipe. This flow meter is made by one of the world's leading gas flow meter manufacturers: Panametrics.

The GM868 flow meter for gas is an extremely low maintenance flow meter as it has no moving parts to be worn out, and no parts to collect debris, this means that there is no need to clean, lubricate or do any other routine maintenance. There is also no pressure drop caused by the GM868's transducers, as they do not obstruct the flow, which is a common problem with other types of flow meters.

The GM868 flow meter offers either analogue and digital output options, which make it easy for the user to have the data sent to where it needs to be. There is also the choice of having alarm outputs. These outputs can all be set up and calibrated form the a computer using the Panaview software or from the keypad.

Features and benefits

  • The GM868 can measure all acoustically conductive gases.
  • Very low maintenance flow meter- as it has no moving parts.
  • The GM868's transducers do not cause pressure drops.
  • Suitable for high temperature use.
  • Has a choice of digital or analogue outputs which can be set up from the keypad or computer.
  • Single channel or dual channel meters available (allows flow measurement in two points in the same pipe or in two separate pipes)
  • Wide pipe size range of 1 inch to 120 inches.

Manufactured by: Panametrics
Model: GM868 Ultrasonic Gas Flow Meter

Services offered for this product

  • Sales
  • Rental
  • Installation
  • Calibration
  • Maintenance


Hydrocarbon gases
Vent gases
Digester gases
Fuel gases
Waste gases
Incinerator air flow
Vapor recovery
Stack gases
Other gases


Operation and Performance
Fluid Types All acoustically conductive gases
Pipe Sizes 2 in to 120 in (50 mm to 3,000 mm) NB and larger
Pipe Materials All metals. Consult GE for other materials.
Flow Accuracy (Velocity) ±1% to 2% of reading typical
Accuracy depends on pipe size and whether measurement is one-path or two-path. Accuracy to ±0.5% of reading may be achievable with process calibration.
Repeatability ±0.2% to 0.5% of reading
Range (Bidirectional) -150 to 150 ft/s (-46 to 46 m/s)
Rangeability (Overall) 150:1
Specifications assume a fully developed flow profile (typically 20 diameters upstream and 10 diameters downstream of straight pipe run) and flow velocity greater than 3 ft/s (1 m/s).
Measurement Parameters Mass flow, standard and actual volumetric flow, totalized flow, and flow velocity
Flow Measurement Patented Correlation Transit-Time mode
Enclosures - Standard: Epoxy-coated aluminum weatherproof Type 4X/IP66 Class I, Division 2, Groups A,B,C&D
- Optional: Stainless steel, fiberglass, explosion-proof, flameproof
Dimensions Standard: Weight 11 lb (5 kg), size (h x w x d) 14.24 in x 11.4 in x 5.12 in (362 mm x 290 mm x 130 mm)
Channels - Standard: One channel
- Optional: Two channels (for two pipes or two-path averaging)
Display Two independent software-configurable 64 x 128 pixel backlit LCD graphic displays
Keypad 39-key membrane keypad
Power Supplies Standard: 100 to 130 VAC, 50/60 Hz or 200 to 265 VAC, 50/60 Hz
Optional: 12 to 28 VDC, ±5%
Power Consumption 20W maximum
Operating Temperature -4° to 131°F (-20° to 55°C)
Storage Temperature -67° to 167°F (-55° to 75°C)
Standard Inputs/Outputs Two 0/4 to 20 mA isolated outputs, 550 S maximum load
Optional Inputs/Outputs There are six additional slots available for any combination of the following I/O boards:
- Analog outputs: Select up to three additional output boards, each with four isolated 0/4 to 20 mA outputs, 1kS maximum load
- Analog inputs: Select up to three boards of one of the following types:
- Analog input board with two isolated 4 to 20 mA inputs and 24V loop power
- RTD input board with two isolated, three-wire, RTD inputs; span -100° to 350°C (-148° to 662°F); 100 S
- Totalizer/frequency outputs: Select up to three totalizer/frequency output boards, each with four outputs per board, 10 kHz maximum
- Alarm relays: Select up to two boards of one of the following types:
- General purpose: Relay board with three Form C relays
- Hermetically sealed: Relay board with three hermetically sealed Form C relays
Digital Interfaces - Standard: RS232 - Optional: RS485 (multiuser)
- Optional: Modbus® RS485 or TCP protocol
- Optional: Ethernet
- Optional: OPC server
- Optional: Foundation fieldbus
Data Logging Memory capacity (linear and/or circular type) to log over 43,000 flow data points
Display Functions - Graphic display shows flow in numerical or graphic format
- Displays logged data and diagnostics
European Compliance Complies with EMC Directive 89/336/ EEC, 73/23/EEC LVD (Installation Category II, Pollution Degree 2) and PED 97/23/EC for DN<25

Wetted Ultrasonic Flow Transducers

Temperature Ranges - Standard: -58° to 302°F (-50° to 150°C)
- Optional (overall range): -310° to 842°F (-190° to 450°C)
Pressure Ranges - Standard: 0 to 2,700 psig (1 to 187 bar)
- Optional: 3480 psig (240 bar) maximum
Transducer Materials - Standard: Titanium
- Optional: Monel® or Hastelloy® alloys
Process Connections Flanged and compression fittings
Mountings Flanged flowcell or cold tap
Area Classifications - Standard: General purpose
- Optional: Weatherproof Type 4X/IP66
- Optional: Explosion-proof Class I, Division 2, ATEX
Transducer Cables One pair of RG62 AU coaxial cables, 1000 ft (330 m)
High-Temperature and High-Pressure Ultrasonic Flow Transducers Bundle Waveguide Technology System transducer and holder (see BWT System specifications) Pressure and temperature transducers available on request.