SCHMIDT® Flow Sensor SS 20.651

  • Chamber head (fast response time)
  • Flow and temperature signal
  • Probe length 250 … 1,000 mm
  • Remote sensor (optional)
  • Measuring ranges 0 … 2.5 m/s to 0 … 60 m/s
  • Pulse output
  • Profi-BUS DP-V0 and DeviceNet (optional)
  • Pressure resistant up to 16 bar
  • Temperature range +350 °C

 

In many areas the measurement of the flow velocity and / or the volume flow at higher temperatures of up to +350 °C is very important in terms of energy efficiency, quantity detection and plant control.

 

Mechanically rugged, precise and long-term stable measurement values ​​as well as different installation sites

 

  • Drying processes
  • Engine test stands
  • Industrial burners
  • Control of the combustion air

 

SCHMIDT® Technology - simply a question of better measurement

Specifications

Technical data
Measuring quantityStandard flow velocity wN, based on standard conditions 1)
Medium temperature TM
Measured mediumClean air, nitrogen, other gases upon request
Measuring range flow wN0 … 10 / 20 / 40 / 60 m/s
Lower detection limit flow wN0.2 m/s (at TM = 20 °C)
Measuring range temperature TM0 … +200 / +350 °C
Recovery time wN< 10 s (after temperature change of ∆ϑ = 40 K and at wN = 5 m/s in air)
Operating temperature
Sensor head0 … +200 / 0 … +350 °C (optional)
Electronics-20 … +70 °C
Storage temperature-20 … +85 °C
Material
HousingAluminium, anodised
Sensor tubeStainless steel 1.4571
Sensor headPlatinum resistor element (glass-passivated), ceramics
Compression fittingStainless steel 1.4571 or brass (depending on sensor option)
Measuring accuracy
Standard wN± (3 % of measured value + [0.4 % of fmr; min. 0.08 m/s]) 1)
High precision (optional) wN± (1 % of measured value + [0.4 % of fmr; min. 0.08 m/s]) 1)
Response time (t90) wN3 s (jump of wN from 0 to 5 m/s in air)
Temperature gradient wN< 8 K/min (at wN = 5 m/s in air)
Temperature TM (wN > 2 m/s)± 2 K (TM = 10 ... 30 °C)
± 4 K (in remaining measuring range)
General data
HumidityMeasuring mode: Non-condensing (< 95 % RH); high relative air humidity in combination with high temperature can cause measurement deviations
Operating pressure (max.)Atmospheric (700 … 1,300 hPa) / 16 bar (optional; over pressure)
Display4 x Duo-LEDs (green / red / orange)
Supply voltage24 V DC ± 20 %
Current consumptionTyp. 50 mA (max. 250 mA)
Start up timeApprox. 10 s after switch-on
Analog outputs for wN and TM
(type: Auto U / I)
Auto-U/I: 0 … 10 V / 4 … 20 mA (signal characteristic depends on RL)
Voltage output: RL ≥ 550 Ω (short-circuit protected)
Current output: RL ≤ 500 Ω
Change-over hysteresis: 50 Ω
CL ≤ 10 nF
Pulse outputs: Signalization0 … 100 Hz or 1 impulse / m3 or free selectable frequency (10 … 100 Hz)
Pulse outputs: Technology1. Highside-driver (open collector at protected supply voltage; not galvanically isolated)
High level: > supply voltage - 3 V
2. Semiconductor relay (galvanically isolated), max. 30 V / 50 mA
Fieldbus (optional)Profibus DP / DeviceNet
Electrical connectionPlug-in connector M12 (A-coded), male, 8-pole (shielded), screwed
Maximum cable lengthVoltage interface: 15 m
Current interface (pulse outputs): 100 m
Mounting positionArbitrary (atmospheric; under higher pressure preferred horizontally)
Mounting tolerance± 3° relative to flow direction
Type / class of protectionIP65 (housing), IP54 (probe) / III (SELV) or PELV (EN 50178)
Probe length250 / 400 / 600 / 1,000 mm (for both: compact probe and remote probe)
Weight550 g max. (400 mm input length) / 800 g (field bus version)
Cable length (remote version)Selectable: 1 … 10 m (in steps of 1 m)

1) Standard velocity wN based on standard conditions of 20 °C and 1,013.25 hPa, related to adjustment reference; fmr = final measuring range

Subject to technical changes.

Order information

 DescriptionArticle number
Basic sensorSCHMIDT® Flow Sensor SS 20.651546650-ABCDEFGHDD
 Options
 Standard 1        

Output signals

Basic (2 x analogue auto-U/I plus 2 x impulse)  1       
Profibus DP-V0  2       
DeviceNet  3       
Mechanical versionBasic (compact version with fixed probe)   1      
Remote version with cable length: _____ mm (1 ... 10 m)   2      
Probe length 250 mm    1     
Probe length 400 mm    2     
Probe length 600 mm    3     
Probe length 1,000 mm    4     
Measuring range and adjustmentMeasuring range 0 ... 2.5 m/s     1    
Measuring range 0 ... 10 m/s     2    
Measuring range 0 ... 20 m/s     3    
Measuring range 0 ... 40 m/s (only at H = 3 or 4)     4    
Measuring range 0 ... 60 m/s (only at H = 3 or 4)     5    
Standard adjustment      1   
Standard adjustment with factory calibration certificate      3   
High precision adjustment, including factory calibration certificate      2   
Impulse outputStandard: wN ~ f = 0 ... 100 Hz (wN, max = fmax)       1  
1 Impulse/m3 for pipe diameter (round): _____ mm (min. 20 mm)       2  
Selectable fmax: _____ Hz (10 ... 100 Hz)       9  
Temperature and pressure200°C atmospheric        1 
200°C atmospheric (coated)        2 
200°C pressure-tight        3 
200°C pressure-tight (coated)        4 
350°C atmospheric        5 
350°C pressure-tight        6 
Pressure DD: ___ (00 ... 16 bar; 00 = atmospheric; > 1 bar overpressure)         00 … 16

Accessories

Connection technology

DescriptionArticle-Number
Connecting cable 8-pin, length 5 m, with coupler socket and open cable ends524 921
Coupler socket 8-pin, cable length selectable, (2 … 100 m; 1-m-steps), free of halogen, with cable end sleeves524 942
Coupler socket 8-pin, with screw connections, for cable diameter ø 6 ... 8 mm524 929
Power supply: out 24 V DC / 1 A; in 115 / 230 V AC (strip terminal)535 282

Mounting and fixing technology

DescriptionArticle-Number
Compression fitting SS 20.651 HT-p = 350 °C525 734
Welding sleeve G½, steel, according to EN 10241, 5 pieces524 916
Welding sleeve G½, stainless steel 1.4571, to EN 10241, 2 pieces524 882
Assembly kit for pipe assembly suitable for MD 10.010/10.015, including pipe clamps and collar for adjustment for the pipe diameter531 394

Measured value display

DescriptionArticle-Number
LED display MD 10.010 in wall housing to show volume flow and flow velocity, 85 … 250 V AC and sensor power supply527 320
LED display MD 10.010, similar to 527 320 but with 24 V DC voltage supply528 240
LED display MD 10.015, similar to 527 320 but with an additional sum function and a second measuring input527 330
LED display MD 10.015, similar to 527 330 but with 24 V DC voltage supply528 250

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