SCHMIDT® Flow Sensor SS 20.250

The smallest all-rounder – universal and powerful

 

  • Dumb-bell head (largely independent from flow direction, easy to clean)
  • Flow and 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 the flow velocity and the volume flow in air and gases is the ideal solution. Due to the 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.

 

  • Energy-efficient control of ventilators
  • Monitoring filter units
  • Regulation and control of flow rate for extraction systems
  • 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 flow wN0 … 1 / 10 / 20 m/s;
Special measuring range inbetween 1 … 20 m/s (in steps of 0.1 m/s)
Lower detection limit flow wN0.06 m/s
Measuring range temperature TM-20 … +70 °C
Measuring accuracy
Standard wN± (5 % of measured value + [0.4 % of fmr; min 0.02 m/s])
High precision (optional) wN± (3 % of measured value + [0.4 % of fmr; min 0.02 m/s])
Response time (t90) wN3 s (jump from 0 to 5 m/s of air)
Temperature gradient wN< 2 K/min at 5 m/s
Temperature TM (for wN > 1 m/s)± 1 K (10 … 30 °C);
± 2 K (remaining measuring range)
Operating temperature
Sensor-20 … +70 °C
Electronics-20 … +70 °C
Storage temperature-30 … +85 °C
General data
HumidityMeasuring mode: Non-condensing (< 95 % RH)
Operating pressure (max.)Atmospheric (700 … 1,300 hPa)
DisplayDual-LED green / red
Supply voltage24 V AC/DC ± 10 %
Current consumptionTypical < 60 mA, max. 100 mA
Analog outputs for wN and TM
(type: Auto U / I)
Auto U/I: 0 … 10 V / 4 … 20 mA (signal characteristic depends on RL)
Voltage output: RL ≥ 550 Ω (short-circuit protected)
Current output: 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 connectionStandard:
Non-detachable cable, 5 wires, length 2 m or selectable (3 … 100 m; steps of 1 m)

Hygienic Design Option:
Cable fix linked to sensor: 1.5 m, 5 pole M12 plug;
Additional content of delivery: cable 10 m, 5 pole M12 bushing
Maximum cable lengthVoltage interface: 15 m<brCurrent interface: 100 m
Mounting positionArbitrary
Minimum immersion depth58 mm (< 58 mm upon request)
Protection type / classIP65 / III or PELV (EN 50178)
Probe length300 / 500 mm
Weight200 g max.
Material
Sensor tubeStainless steel 1.4571
Sensor headPBT glass-fiber-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) based on standard conditions: 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 20.250; 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, not available for Hygienic Design version)    2 
With protactive coating (Parylene, 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 24 V/1 A DC (output), 115/230 V AC voltage supply535 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 Dec voltage supply528 240
SCHMIDT® LED display MD 10.015, similar to 527320 but with an additional sum function and a 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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