SCHMIDT® Flow Sensor SS 20.420

Thermal flow sensor for unidirectional or bidirectional measurement of the flow rate of air with simultaneous detection of the flow direction.

 

  • Thermopile head (very fast response time)
  • Flow signal
  • Probe length 60 and 110 mm
  • Measuring ranges 0 … 1 m/s to 0 … 10 m/s
  • Bi-directional measurement (detection of flow direction, optional)
  • 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.

 

  • Plant and mechanical engineering
  • Semiconductor and electronics manufacturing
  • Cleanroom and pharmaceutical
  • Ultra-compact design

 

SCHMIDT® Technology - simply a question of better measurement

Specifications

Technical data
Measuring quantityStandard flow velocity wN, based on standard conditions1)
Measured mediumClean air or nitrogen
Measuring range flow wN0 … 1 / 2.5 / 5 / 10 m/s
Lower detection limit flow wN0.05 m/s
Measuring accuracy
Standard wN± (5 % of measured value + [1 % of fmr; min. 0.05 m/s]) 1)
High precision (optional) wN± (3 % of measured value + [1 % of fmr; min. 0.05 m/s]) 1)
Response time (t90) wN0.2 s
Operating temperature
Sensor0 … +60 °C
Storage temperature-20 … +85 °C
General data
HumidityMeasuring mode: Non-condensing (< 95 % RH)
Operating pressure (max.)Atmospheric (700 … 1,300 hPa)
Supply voltage24 V DC ± 10 %
Current consumptionTyp. < 6 mA (max. 10 mA)
Analog output0 … 10 V (RL ≥ 10 kΩ;; CL ≤ 1 nF; short-circuit protected)
Electrical connectionNon-detachable cable, 3 wires, length 5 m, with ferrules
Maximum cable length15 m
Protection type / classIP65 / III or PELV (EN 50178)
Probe length60 mm / 110 mm (order option)
Material
Sensor headØ 9 mm x 10 mm stainless steel 1.4404
Sensor tubeØ 9 mm stainless steel 1.4404

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 20.420 basic version: wN; cable 5 m; output signal: 0 … 10 V538 045 -A1CDEF
 Options
Sensor typeStandard 1     
Mechanical typeSensor length 60 mm  1    
Sensor length 110 mm  2    
Measuring rangeMeasuring range 0 … 1 m/s   1   
Measuring range 0 … 2.5 m/s   2   
Measuring range 0 … 5 m/s   3   
Measuring range 0 … 10 m/s   4   
Measurement direction, setting and adjustmentUnidirectional – standard adjustment (5-%-class)    1  
Unidirectional – standard adjustment with factory calibration certificate (5-%-class)   5  
Bidirectional – standard adjustment (5-%-class), representation of direction with halved analog signal: 0 m/s = 5 V output signal (analog output 50 %)    2  
Bidirectional – standard adjustment with factory calibration certificate (5-%-class), representation of direction with halved analog signal: 0 m/s = 5 V output signal (analog output 50 %)    6  
Unidirectional – high precision adjustment with factory calibration certificate (3-%-class)    3  
Bidirectional – high precision adjustment with factory calibration certificate (3-%-class), representation of direction with halved analog signal: 0 m/s = 5 V output signal (analog output 50 %)    4  
Analog output0 … 10 V     1 
Connection cable5 m cable with open ends      1

Accessories

Connection technology

DescriptionArticle-Number
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
Wall mounting bracket, material aluminium anodized503 895
Mounting flange, stainless steel 1.4404551 740
Compresson fitting, stainless steel G½, atmospheric pressure532 160
Welding sleeve, stainless steel 1.4571, G½, according 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
SCHMIDT® LED display MD 10.010; in the wall housing to visualize the volumetric flow and the flow velocity (or other measures), 85…250 V AC and sensor supply527 320
SCHMIDT® LED display MD 10.010; as with 527 320 but with 24 V DC voltage supply528 240
SCHMIDT® LED display MD 10.015; in the wall housing to visualize the volumetric flow and the flow velocity (or other measures), with additional sum function and second measuring input, 85 … 250 V AC and sensor supply527 330
SCHMIDT® LED display MD 10.015; as with 527 330 but with 24 V DC voltage supply528 250

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