Vortex Flow Sensors VA
 
Vortex Flow Sensors VA  
Principle of measurement
 
Instrumentation  
 
Vortex flow sensors VA  
 
VA-Di Measuring Tubes  
 
Evaluation units  
 
Housings  
 
Principle of measurement up    
   
Principle of measurement Derived from the Karman phenomenon of vortex shedding, the principle of measurement is based on vortices being shed when a flowing medium reaches a rod-shaped obstruction, whereby the vortex shedding frequency is a dimension for the flow velocity.

The flow vortices are ultrasonically scanned. In this way, compared to other scanning methods, flow velocities of as little as 0.5 m/s can be measured coupled with turndown ratios of 1 : 160. The vortices modulate the ultrasonic beam between an ultrasonic transmitter and receiver. The vortex frequency results from the demodulation.

A crucial advantage of the principle of measurement lies in the independence of density, pressure and temperature from the working medium.
Principle of measurement Vortex flow sensors VA have no moving parts, have outstanding fatigue strength even in rough conditions, excellent repeatability, long-term stability and are overload-proof. Measuring is practically inertia-free. The length of cable between sensor and evaluation unit can measure up to several hundred meters.


Solids are of no impairment as long as abrasion does not occur. In comparison to the vane wheel flow sensors, vortex flow sensors can be used for measuring in gases with considerably intensive solids content, without impairing the fatigue strength.

The pictured sensor with salt deposits was installed in a mine for several weeks. The slight deposits on the strut can easily be seen. In soiled condition drifts of max. +/-0.3 m/s result for velocities of up to approx.
12 m/s.

Instrumentation up
A combination of vortex flow sensor VA and a suitable evaluation unit is necessary for successful measuring.
Vortex flow sensors VA up
Vortex flow sensors VA
   
 

Vortex flow sensors VA
Insertion probes for measurement of flow
   
  Vortex flow sensors VAT
Insertion probes for combined measurement of flow and temperature
   
Vortex flow sensors VAR    
Vortex flow sensors VAR
Twin vortex flow sensor for measuring the flow velocity and the ±
direction of flow, for example in traffic tunnels
Designs of vortex flow sensors VA40
Designs of vortex flow sensors VA40
   
  Drawing ZG2: extendable probe with probe tube diameter of 42 mm for greater insertion depths
   
  Drawing ZG4: probe with probe tube diameter of 20 mm, with sliding probe guide piece
for installation in pipelines/ducts
 
   
  Drawing ZG5: probe with probe tube diameter of 20 mm, with lapped flange and welded, integral flange
for making contact with the medium
   
  Drawing ZG6: probe as drawing 5, with EEx ia IIC T6 type of protection for use in zone 0
   
  Drawing ZG7: probe with probe tube diameter of 20mm with sliding probe guide piece for installation in pipelines/ducts;
probes with an installation length of 500 mm or 1000 mm, probe materia stainless steel for use in non-hazardous areas
   
Types of vortex flow sensors VA
 
  initial smallest measurable value approx. 0.5 m/s
   
  terminal measurable value: 40 m/s; 60 m/s and 80 m/s
   
  working temperature range: -20 °C...+100 °C; +180 °C; +240 °C
   
  maximum working pressure: 3 bar above atmospheric
   
  explosion-proof type of protection: EEx ia IIC T6 for zones 1 and 0
   
  probe materials: stainless steel, titanium, tantalum and HASTELLOY
   
  necessary diameter of insertion opening: 40 mm
   
Accessories for vortex flow sensors VA
 
  probe tubes of 350, 500 and 1000 mm length for screwing onto VA probes as in drawing 2
   
  probe guide pieces with flange or screw thread connection, for installation of VA sensors in pipelines and ducts as in drawings 2 and 4
   
  direction indicator for clamping onto the probe tube as in drawing 2,
may also be used as a depth indicator
TA-Di Measuring Tubes up
Vortex-Sensors
 
  VA-Di-Messrohre

measured values from 0.7 m³/h and 0.4 m/s
 

working temperature range –10 ... 180 °C
 

maximum working pressure 10 bar / 1 MPa above atmospheric
 

material stainless steel, titanium, Hastelloy
 

measuring uncertainty < 1% of test value + 0.2 % full scale
 

consistency +/- 0.2%
   
 

available with integrated transducer
   
 

Di

Measuring range volume flow

Measuring range flow velocity

[mm]

[m³/h]

[m/s]

25

0,7 ... 71

0,4 ... 40

40

1,8 ... 181

0,4 ... 40

50

2,8 ... 283

0,4 ... 40

80

7,2 ... 724

0,4 ... 40

100

11,3 ... 1131

0,4 ... 40

Evaluation units up
µP-Flowtherm
     
Vortex-flow sensor FA type
     
  µP-Flowtherm   hand-held instrument for connection of non-direction sensing vortex flow
sensors; with and without integrated/separate temperature sensor
     
    display range: flow velocity in m/s, Nm/s / volume flow in m³/h, l/min,
Nm³/h, Nl/min / temperature in °C
     
    conversion of actual flow variables into standard flow variables by
measuring temperature and inputting working pressure
     
    alternative adjustments by the user: type of sensor, type of medium,
diameter or cross-sectional area of measuring tube, profile factor, pressure of medium, unit of display, measuring mode, duration and commencement of
measurement
     
    outputs: 2 x 0... ± 4 V analog / pulse frequency output level: 0 and 5 V /
RS232-TTL or V24-TTL for connection to an IBM compatible PC via RS232 / V24
adapter
     
    power supply: 9 V lithium-ion battery or plug-in power supply
     
    increasing measurement accuracy of the flow measurement by linearizing
of characteristics by the user
     
    optional data logging also automatic at random time intervals of up to 520
data records; play back via display or RS232 / V24 output
     
    optional accessories: RS232 / V24 adapter for data transmission to an IBM
compatible PC / µP-Flowtherm extension cable 3 m or 5 m long, also with
waterproof connector / µP-Flowtherm Y cable for connection to two sensors at the input of the µP-Flowtherm / µP-Flowtherm carrying case / µP
Flowtherm light metal carrying case / 9 V battery
     
Transducer U2a
     
  Transducer U2a   for connection with vortex flow sensors VA not
sensing direction of flow
     
    without display and keypad
     
    analog output: 4-20 mA, 0-20 mA 0-4 V, 0-10V; optional
     
    power supply: 230 VAC, 110 VAC, 24 VAC, 24 VDC, 12 VDC and
24 VDC optional
     
    designs: LDG16 miniature housing (W/H/D = 55/75/110) for 35 mm standard
assembly rails, aluminium housing AS102 IP65 (W/H/D = 100/75/110 mm)
     
    factory settings: calibration number KKZ of the sensor, scaling the output
       
LDX1A ATEX
     
LDX1A ATEX isolation/supply unit for connection of vortex flow sensors VA in EEx ia IIC T6
type of protection
power supply: 230 VAC, 24 VAC, DC supply with series connected DC/AC
converter possible!
 

LDG16 miniature housing (W/H/D = 55/75/110) for 35 mm standard
assembly rails

 
operation only permissible with non-Ex evaluation units: transducer U2a or
system instrument in LDG30 housing (see below)
LDX1A ATEX and secondary evaluation unit are to be placed in a
non-hazardous space
     
System instruments with display and keypad
     
  System instruments with display and keypad   µP-Vortex
for connection of vortex flow sensors VA
     
    µP-Vortex-R
for connection of direction sensing
vortex flow sensors VAR
     
    VT-VA
for connection of vortex flow sensors VA and Pt100 temperature probes,
pressure as input value
     
    VP-VA
for connection of vortex flow sensors VA and absolute pressure gauges,
temperature as input value
     
    VTP-VA
for connection of vortex flow sensors VA, Pt100 temperature probes
and absolute pressure gauges
   
Types available
 
  optional with Ex-inputs for connection of vortex flow sensors VA, Pt100 temperature probes and pressure gauges in
explosion-proof type of protection (not in LDG30 housing; additional LDX1A Ex-input unit necessary here (see above)
   
  analog output flow (in the case of V(T)(P) instruments optional also pressure, temperature):
0/4-20 mA, 0-5 V, 0-10 V, optional
   
  optional RS232 / V24 output (not in LDG30 housing, see below)
   
  power supply: 230 VAC, 24 VAC, 24 VDC; optional; in the case of system instruments in free-standing housing Ti-SRF
also choice of supply by accumulator
   
  housing variants as below
   
  software options: quantity measurement, long-term measurement, limit value, password, data logger, coefficient 3-point
adjustment, failure monitoring, etc
   
  optional relay output for flow direction or quantity impulse
   
  multi-channel instruments and special designs on request
Housings up
system instruments µP-Vortex, µP-Vortex-R, VT-VA, VP-VA and VTP-VA for connection of vortex flow sensors VA
   
   
  LDG30
  LDG30: miniature housing W/H/D = 100/75/110 mm for 35 mm standard
assembly rails
   
   
  EMV-AH162
 

EMV-AH162:
for wall mounting, protective system IP65, with screwed cable glands, for
installation of 1 evaluation unit in LDG16 housing as well as 1 evaluation
unit in LDG30 housing W/H/D = 240/160/134 mm
   
   
  EMV-AH160
  EMV-AH160:
for wall mounting, protective system IP65, with screwed cable glands, for
installation of 1 evaluation unit in LDG30 housing
   
   
  Wa-IP65
  Wa-IP65: wall-mounted W/H/D = 306/241/264 mm
   
   
  Ti-SRF
  Ti-SRF: free-standing W/H/D =365/155/315 mm
   
   
  19”3HE
  19”3HE: slide-in housing W/H/D = 443/133/317 mm
   
   
  Cassette
  Cassette: 3HE 28TE, 3 cassettes in one empty 19“ housing
up