Suitable for:
- Natural gas
- Compressed air
- Fuel gases
- Corrosive gases
- Toxic gases
- High-purity gases
- Air separation gases
- Speciality gases
The DigitalFlow CTF878 Correlation Tag Clamp-on Gas Ultrasonic Flowmeter is
suitable for metal pipes and for pressure as low as atmospheric. It is non-intrusive,
with no wetted parts and no moving parts. As you won't have to tamper with your
pipework, there is no pressure drop and installation is simple.
The CTF878 uses a new technology called correlation tag, to determine the flow
rate of gases. This is unlike other ultrasonic flowmeters. The kit is supplied
with two pairs of transducers - the first measure upstream disturbance, and
the second (situated downstream) send a signal when they recognise that the
same disturbance pattern has travelled along the pipe. Each pair of transducers
includes a transmitter sending ultrasound in a continuous wave mode through
the fluid to the receiver, forming an upstream and downstream interrogation
path. The continuous wave signal is modulated by turbulence and local density
variations that are characteristic of a moving gas.
In the past, a restricting factor in gas measurement has been the signal strength
of transducers: having to send an ultrasonic signal through the metal pipe wall,
through the gas, and then back through the pipe wall again. New clamp-on gas
transducers produce signals that are five to ten times more powerful than signals
of traditional ultrasonic transducers. This new technology produces clean, strong
signals with marginal background noise.
Specifications assume a fully developed flow profile (typically 20 diameters
upstream and 10 diameters downstream of straight pipe run).
| Fluid Types |
All acoustically conductive gases. Gas should not be saturated with moisture.
|
| Minimum gas density |
0.074 lb/ft3 (1.2kg/m3) |
| Pipe sizes |
6 to 30 in NB (nominal bore) (152mm to 762mm) |
| Pipe Wall Thickness |
Up to Schedule 80 |
| Pipe Materials |
Most metals and plastics, no lined pipes |
| Flow accuracy |
+/- 2% of reading at 3.5 to 150 ft/s (1.1 to 46 m/s typical) |
| Repeatability |
+/- 0.2% to 0.6% at 3.5 to 150 ft/s (1.1 to 46 m/s) |
| Range (bidirectional) |
+/- 150 to +/- 3.5 ft/s (+/-46 to +/- 1.1 m/s) |
