SCHMIDT® Flow Sensor SS 20.250

The smallest all-rounder – universal and powerful

 

  • Patented sensor head (dumb-bell head):

- Largely independent from flow direction

- Easy to clean (free of undercuts)

- Dirt-resistant

  • Flow and medium temperature signal
  • Probe length 300 … 500 mm
  • Measuring ranges 0 … 1 m/s to 0 … 20 m/s, special measuring range
  • Optional coated (not for Hygienic Design version)
  • Hygienic Design version optional

 

In many applications, the direct measurement of flow velocity or volume flow in air and gases is the ideal solution.

Due to high demands of modern control technology, the flow sensor has to detect precisely and fast an extremely wide measuring range from "almost zero" up to the maximum value.

 

For clean room applications also available as SS 20.250 Hygienic Design (order option):

  • Smooth surface (free of undercuts) prevents product or dirt residues
  • Corrosion resistant (stainless steel V4A)
  • Easy to clean
  • Resistant to all commercially available cleaning agents
  • Easy to remove for calibration due to plug-in connection

- Sensor with 1.5 m Hygienic Design cable and plug

- Additional 10 m Hygienic Design cable with socket included

 

  • Ventilation and air conditioning
  • Clean room and pharma
  • Monitoring of FFUs
  • Monitoring of laminar flow in cleanrooms

 

SCHMIDT Technology – simply a question of better measurement

Specifications

Technical data
Measuring quantityStandard flow velocity wN based on standard conditions 1)
Temperature of medium TM
Measured mediumAir or nitrogen, other gases upon request
Measuring range wN0 … 1 / 10 / 20 m/s;
Special measuring range inbetween 1 … 20 m/s (steps of 0.1 m/s)
Lower detection limit wN0.06 m/s
Measuring range TM-20 … +70 °C
Measuring accuracy
Standard wN±(5 % of measured value + [0.4 % of fmr; min 0.02 m/s]) 2)
High precision (optional) wN±(3 % of measured value + [0.4 % of fmr; min 0.02 m/s]) 2)
Response time (t90) wN3 s (jump from 0 to 5 m/s in air)
Temperature gradient wN< 2 K/min (at wN = 5 m/s in air)
TM (for wN > 1 m/s)±1 K (10 … 30 °C); ±2 K (remaining measuring range)
Operating temperature
Sensor / electronics-20 … +70 °C
Storage temperature-30 … +85 °C
General data
HumidityMeasuring mode: Non-condensing (< 95 % RH)
Operating pressureAtmospheric (700 … 1,300 hPa)
DisplayDual-LED:
- Green: Status
- Red (flashing): Sensor defective
Supply voltage24 V AC/DC ± 10 %
Current consumptionTypical < 60 mA, max. 100 mA
Analog outputs
Type: Auto U / I)
wN, TM
0 … 10 V / 4 … 20 mA (switching of signal characteristic depends on RL)
-Voltage output (0 … 10 V): RL ≥ 550 Ω (short-circuit protected)
- Current output (4 … 20 mA): RL ≤ 500 Ω
- Change-over hysteresis: 50 Ω
- CL ≤ 10 nF
Voltage output: RL ≥ 500 Ω

Current output: RL ≤ 500 Ω

Hysteresis: 50 Ω
Electrical connectionNon-detachable cable, 5 x 0,25 mm2
Standard: Length 2 m or selectable (3 … 100 m; steps of 1 m), with ferrules
Hygienic Design Option: 1.5 m, M12 plug (male, A-coded, 5 pole);
Additional content of delivery: Cable 10 m, M12 bushing (female, A-coded, 5 pole)
Maximum cable lengthVoltage interface: 15 m; current interface: 100 m
Mounting positionArbitrary
Minimum immersion depth58 mm (< 58 mm upon request)
Protection typeIP65
Protection classIII (SELV) or PELV (EN 50178)
Probe length300/500 mm
Weight200 g max.
Material
Sensor tubeStainless steel 1.4571
Sensor headPBT (glass-fibre reinforced), stainless steel 1.4571
Protective coating (optional)Polyurethan / parylene (coating not available for Hygienic Design version)
Sensor cableStandard: PUR, halogen-free
Hygienic Design Option: PP-EPDM, halogen-free

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 20.250; 2 x output signal 4 … 20 mA and 0 … 10 V; cable length 2 m526 340-XYZPA
 Options
Mechanical typeSensor length 300 mm 1    
Sensor length 500 mm 2    
Measuring range, adjustment accuracy and calibrationMesuring range 0 … 1 m/s  1   
Mesuring range 0 … 10 m/s  2   
Mesuring range 0 … 20 m/s  3   
Special measuring range (1 … 20 m/s; 0.1 m/s)  9   
Standard adjustment   1  
Standard adjustment with factory calibration certificate   3  
High-precision flow adjustment, including factory calibration certificate   2  
Protection typeWithout protective coating    1 
With protactive coating (Polyurethan derivate black; sensor head only; not available for Hygienic Design version)    2 
With protactive coating (Parylene transparent; fully coated besides ca. 40 mm at the cable end; not available for Hygienic Design version)    3 
Connecting cableCable length 2.0 m     1
Special cable length: 3 ... 100 m; 1 m steps     2
Hygienic design cable with fix linked to sensor 1.5 m, 5-pol M12 plug-in connector; additional content of delivery: 10 m hygienic design cable, 5-pol M12 bushing     3

Accessories

Connection technology

DescriptionArticle-Number
Power supply unit: output 24 V / 1A DC, supply voltage 115/230 V AC (strip terminal)535 282

Mounting and fixing technology

DescriptionArticle-Number
Mounting flange, steel, galvanic zinc-plated301 048
Wall-mounting flange, stainless steel, PTFE-clamping ring520 181
Compression fitting, stainless steel, G½, atmospheric pressure532 160
Compression fitting, brass, G½, atmospheric pressure517 206
Welded sleeve, steel, G½, according to EN 10241, 5 pieces524 916
Welded sleeve, stainless steel 1.4571, G½, according to EN 10241, 2 pieces524 882
Adapter M18 x 1, G½545 090
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 wall housing to show the volume flow velocity, 85 … 250 V AC and sensor power supply527 320
SCHMIDT® LED display MD 10.010, similar to 527320 but with 24 V DC voltage supply528 240
SCHMIDT® LED display MD 10.015, similar to 527320 but with additional sum function and second measuring input527 330
SCHMIDT® LED display MD 10.015, similar to 527330 but with 24 V DC voltage supply528 250

Miscellaneous

DescriptionArticle-Number
Attachable protective clip for dumbbell head against mechanical influences, stainless steel531 026
Attachable protective 2-wires-clip for protection against mechanical influences,
stainless steel, H2O2-resistant
559 124

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