SCHMIDT® Flow Sensor SS 20.400

Thermal flow velocity sensor for uni- or bidirectional measurement of air and gases with simultaneous detection of flow direction.

 

  • Thermopile head (very fast response time)
  • Flow velocity and switching signals
  • Probe length 130 … 300 mm
  • Measuring ranges 0 … 1 m/s to 0 … 20 m/s
  • Bidirectional measurement (optional)
  • Detection of flow direction (optional)
  • Optimized adjustment for LF-applications (optional)
  • Sensor programming (optional)
  • Cleanroom sensor
  • Extremely compact (electronics is integrated in sensor tube)
  • Sensor element protected against mechanical stress
  • Linear analog output for measured flow velocity
  • Two switching outputs to signal flow direction and threshold

 

  • Clean rooms and pharma
  • Laminar flow monitoring in flow boxes
  • Monitoring of cleanroom overflow
  • Cooling air monitoring
  • Flow measurement in test benches

 

SCHMIDT Technology – Simply a question of better measurement

Specifications

Technical data
Measuring quantityStandard flow velocity wN, based on standard conditions 1)
Measured mediumClean air or nitrogen, additional gases on request
Measuring range wN(±)0 … 1 / 2.5 / 5 / 10 / 20 m/s (uni- or bidirectional)
Lower detection limit wN(±)0.05 m/s
Measuring accuracy
Standard wN±(3 % of measured value + [2 % of fmr; min. 0.05 m/s]) 2)
High precision (optional) wN±(1 % of measured value + [2 % of fmr; min. 0.04 m/s]) 2)
Response time (t90) wN1 s (configurable: 0.01 ... 10 s)
Operating temperature
Sensor0 … +60 °C
Storage temperature-20 … +85 °C
Material
Sensor headStainless steel 1.4404
Sensor tubeStainless steel 1.4404
Plug-in connector, nut screwStainless steel 1.4404
General data
HumidityMeasuring mode: Non-condensing (< 95 % RH)
Operating pressureAtmospheric (700 … 1.300 hPa)
Supply voltage12 … 26.4 V DC
Current consumptionTypical < 35 mA (max. 150 mA, current of switching outputs included)
Analog output wN0 … 10 V (RL > 10 kΩ; CL ≤ 10 nF; short-circuit protected)
4 … 20 mA (RL < 300 Ω; CL ≤ 100 nF)
Switching outputs2 x open collector (at GND), current-limited and short-circuit protected, configurable
-Channel 1 (OC1): Flow direction or threshold value
- Channel 2 (OC2): Threshold value
- External switching voltage / current: Max. 26.4 V DC / 55 mA (typ. 50 mA)
- Hysteresis: 5 % of threshold value (min. ±0.05 m/s)
Electrical connectionPlug-in-connector M9, male, 7-pin (shielded), screwed
Maximum cable lengthVoltage interface: 10 m; current interface: 100 m
Mounting position±3° relative to flow direction (uni- or bidirectional)
Protection typeSensor probe: IP66; electrical connector: IP67 (with correct attached cable)
Protection classIII (SELV) or PELV (EN 50178)
Sensor length L130/200/300 mm
WeightApprox. 60 g max. (L = 300 mm)

1) Standard conditions: TN = 20 °C and pN = 1,013.25 hPa

2) Related to adjustment reference; "fmr" = final measuring range

Subject to technical changes

Order information

 DescriptionArticle-Number
Basic sensorSCHMIDT® Flow Sensor SS 20.400, thermopile head
(also available as: ATEX version (cat. 3G, zone 2; please refer to SS 23.400 ATEX)
518 210 -XYDZR-P
 Options
Mechanical typeSensor length 130 mm(only available with 0…10V output signal) 1      
Sensor length 200 mm 2      
Sensor length 300 mm 3      
Measurement rangeMeasurement range 0 … 1 m/s  1     
Measurement range 0 … 2.5 m/s  2     
Measurement range 0 … 5 m/s  3     
Measurement range 0 … 10 m/s  4     
Measurement range 0 … 20 m/s  5     
Measurement direction, adjustment accuracy and calibrationUnidirectional – standard adjustment   1    
Unidirectional - default adjustment with factory calibration certificate   6    
Bidirectional – standard adjustment   2    
Bidirectional - default adjustment with factory calibration certificate   7    
Unidirectional – high precision adjustment incl. factory calibration certificate   3    
Bidirectional – high precision adjustment incl. factory calibration certificate   4    
Unidirectional LF - optimized for Laminar Flow application, high precision, with factory calibration certificate (only for measuring range 1 m/s)   5    
Analog output0 … 10 V    1
   
4 … 20 mA (not for sensor length 130 mm)    5
   
Representation of directionBidirectional switching output OC 1     1  
Bidirectional: halved analog signal 0 m/s = 12 mA / 5 V     2
  
Unidirectional     3  
Sensor-programmingFactory setting       S
Customer-specific programming of switching polarity, splitting signal and response time       K

Accessories

Connection technology

DescriptionArticle-Number
Plug-in power supply 24 VDC / 1 A output, 100-240 VAC, 2 m cable length, M12-plug connector (screwed, only usable with "Interface Splitter 4xx")571630 + splitter
Coupler socket, 7-pin with soldering sleeves for cable Ø 0.14 mm2535 278
Connection cable with coupler socket, 7-pin, 5 m length, open cable ends, material PUR535 279
Connection cable with coupler socket, 7-pin, length selectable (2 … 100 m; 1 m steps), open cable ends
open cable ends (length 2 … 100 m; 1-m-steps)
505 911 - 4
Connecting cable with angled socket, 7-pin, 10 m length, open cable ends, material PUR535 281
Power supply unit: output 24 V / 1A DC, supply voltage 115/230 V AC (strip terminal)535 282

Mounting and fixing technology

DescriptionArticle-Number
Wall mounting flange, stainless steel, clamping ring PTFE520 181
Compression fitting, stainless steel, G½, atmospheric pressure532 160
Wall mounting bracket, aluminium anodized503 895
Mounting flange, stainless steel 1.4404551 740
Assembly kit for pipe assembly suitable for MD 10.010/10.015 including pipe clamps and collar for adjustment to pipe diameter531 394

Measured value display

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

Miscellaneous

DescriptionArticle-Number
Calibrator MK 40.415 - Set (8 / 12 / 16 mA)546 741 - 4

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