SCHMIDT® Flow Sensor SS 20.415 LED

Thermal flow sensor for uni- or bi-directional measurement of the flow rate of air and gases with simultaneous detection of the 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. Operating status indication and serial number of the sensor visible on the sensor, even when it is installed. Special version for the laminar-flow monitoring in cleanrooms with quick-mounting system for simple installation in cleanroom ceiling systems and walls.

 

Option: Monitoring of the speed interval of 0.45 m/s ±20 % (prescribed by official standards) with optical signaling at the sensor (LF status indicator).

 

  • Laminar flow monitoring in clean rooms
  • Flow monitoring in pharmaceutical production, semiconductor manufacturing, food production, LCD manufacturing and optical industry
  • Integration into insulators, FFUs and flow boxes

Specifications

Technical Data
Measurement quantityStandard flow velocity wN, based on standard conditions of TN = 20 °C and pN = 1,013.25 hPa
Measured medium Clean air, nitrogen, additional gases on request
Measurement range wN0 … 1 / 2.5 / 10 m/s
Max. display range wN+ 10 % above measurement range
Lower detection limit wN0.05 m/s
Measurement accuracy
Default wN± (3 % of measured value+ 0.05 m/s) 1)
High precision (optional) wN± (1 % of measured value + 0.04 m/s) 1)
Repeatability wN± 1.5 of measured value
Response time (t90) wN1 s (configurable: 0.01 ... 10 s)
Temperature gradient wN< 2 K/min at 5 m/s
Operational 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 voltage24 V DC ± 10 %
Current consumptionTyp. 30 mA / max. 160 mA (including all signal output currents)
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
(<26.4 V DC / 65 mA)
Channel 1 (OC1): direction or threshold value
Channel 2 (OC2): threshold value
Switching hysteresis 5 % of the threshold value, min ± 0.05 m/s
Error signalOnly with current interface: 2 mA (according to NAMUR NE43)
Electrical connectionPlug-in-connector M9, male, 7-pin (shielded), screwed
Maximum line lengthVoltage interface: 15 m / current interface: 100 m
Mounting positionIn vertical flow direction
Protection type / classIP65 / III or PELV (EN 50178)
Sensor lengthAngled: 270 x 300 mm / straight: 300 mm or customer-specific until 1000 mm
WeightApprox. 200 g (angular version)

1) under reference conditions

Subject to technical changes.

Order information

 DescriptionArticle-Number
Basic sensorSCHMIDT® Flow Sensor SS 20.415 version as thermopile head551 490 -A1CDEFGHI
 Options
Mechanical typeSensor length 150 x 300 mm 3        
Sensor length 270 x 300 mm 1        
Sensor length 300 mm (straight) 2        
special length (only straight:) ___________ mm (>300 … 1,000 mm; 10-mm-steps) 9        
ProtectionWithout protective coating  1       
Mechanical fixingThreaded bush M25 with counternut   1      
Threaded bush M25 with thread adapter M25 x 1.5 to PG21   2      
Threaded bush M25 with shank nut   3      
Welding bush   4      
Flange bush   5      
Without fixation material   6      
Measurement rangeMeasurement 0 … 1 m/s    1     
Measuring range 0 … 1 m/s, unidirectional, with option LED indication of threshold monitoring (0.45 m/s ±20 %)    4     
Measurement 0 … 2.5 m/s    2     
Measurement 0 … 10 m/s    3     
Measurement directionUnidirectional     1    
Bidirectional (only SS 20.415)     2    
Representation of the directionUnidirectional      1   
Switching output OC 1 = direction signal (only SS 20.415, bidirectional)      2   
Representation of the direction with halved analog signal: 0 m/s = 8 mA or 5 V output signal (only SS 20.415, bidirectional)      3   
Output signals0 … 10 V       1  
4 … 20 mA       2  
Adjustment accuracy and calibrationStandard adjustment without certificate        1 
Standard adjustment unidirectional with factory calibration certificate        4 
Standard adjustment bidirectional with factory calibration certificate (SS 20.415 LED only)        5 
High precision adjustment incl. factory calibration certificate        2 
High precision adjustment incl. factory calibration certificate, bidirectional        3 
Sensor programmingFactory setting         1
Customer-specific programming (only SS 20.415) of switching polarity, threshold value, splitting signal, response time         2

Accessoroes

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, 7-pin with angled socket, 10 m length, open cable ends, material PUR535 281
Power supply 24 V/1 A DC (output), 115/230 V AC voltage supply535 282

Mounting and Fixing Technology

DescriptionArticle-Number
Assemply kit for tube connection for MD 10.010 / 10.015 with hose clamps and band to adapt it so the tube’s 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

Miscellaneous

DescriptionArticle-Number
Measuring Section Calibrator set (8 / 12 / 16 mA)546 741 - 4

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