SCHMIDT® Flow Sensor SS 20.400

Thermal flow sensor for uni- or bi-directional measurement of the flow rate of air and gases with simultaneous detection of flow direction. Extremely compact, because electronics are integrated into the sensor tube. Sensor element in the chamber head and protected against mechanical stress. Linear analog output for measured value output, two switching outputs to output the flow direction and threshold.

 

  • Laminar flow monitoring in flow boxes
  • Monitoring of clean room overflow
  • Cooling air monitoring
  • Flow measurement in test benches

Specifications

Technical Data
Measurement quantityStandard flow velocity wN, based on standard conditions of TN = 20 °C und pN = 1,013.25 hPa
Measured mediumClean air, nitrogen, additional gases on request
Measurement range wN0 … 1 / 2.5 / 5 / 10 / 20 m/s
Lower detection limit wN0.05 m/s
Measurement accuracy
Default wN± 3 % of measured value + (2 % of of measuring range; min. 0.05 m/s 1)
High precision (optional) wN± 1 % of measured value + (2 % of of measuring range; min. 0.04 m/s 1)
Repeatability wN± 1.5 % of measured value
Resonse time (t90) wN1 s (configurable: 0.01 ... 10 s)
Operating temperature
Operating temperature0 … +60 °C
Storage temperature-20 … +85 °C
Material
Sensor headStainless steel 1.4404
Sensor tubeStainless steel 1.4404
Plug connectorStainless steel 1.4404
General Data
Relative HumidityNon-condensing (≤ 95 % rH)
Operating pressureAtmospheric (700 … 1.300 hPa)
Supply voltage12 … 26.4 V DC
Current consumptionTypical < 35 mA (max. 160 mA with switching outputs)
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 low-side driver (open collector at GND), current-limited and short-circuit protected, configurable
Channel 1 (OC): Direction or threshold value; Channel 2 (OC2): Threshold value
External switching voltage / current: Max. 26.4 V DC / 55 mA (typ. 50 mA)
Switching hysteresis: 5 % of threshold value, min. ± 0.05 m/s
Electrical connectionPlug-in-connector M9, male, 7-pin (shielded), screwed
Maximum line lengthVoltage interface: 10 m / current inferface: 100 m
Mounting positionArbitrary
Protection type / classIP66 / III or PELV (EN 50178)
Sensor length130 / 200 / 300 mm
WeightApprox. 60 g max. (300 mm sensor length)

1) under reference conditions

Subject to technical changes.

Order information

 DescriptionArticle-Number
Basic sensorSCHMIDT® Flow Sensor SS 20.400, version as thermopile head
SCHMIDT® Flow Sensor SS 20.400, version as thermopile head, ATEX version (Kat. 3G, Zone2)
518 210 -XYDZR-P
 Options
Mechanical typeSensor length 130 mm (only with 0…10V output signal available) 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 – vertical flow adjustment with 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
Coupler socket, 7-pin, with soldering sleeves for cable Ø 0.14 mm2535 278
Connection cable with coupler socket, 5 m length, open cable ends, material PUR535 279
Connection cable with coupler socket, length ________ m,
open cable ends (length 2 … 100 m; 1-m-steps)
505 911 - 4
Connection cable with angled socket, 7-pin, length 10 m, open cable ends535 281
Power supply 24 V/1 A DC (output), 115/230 V AC voltage supply535 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, material 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 the 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 an additional sum function and a 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
Measuring Section Calibrator set (8 / 12 / 16 mA)546 741 - 4

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