SCHMIDT® Flow Sensor SS 20.651

Specifications

Technical data
Measuring quantity	Standard flow velocity w_N, based on standard conditions ¹⁾ Medium temperature T_M
Measured medium	Clean air, nitrogen, other gases upon request
Measuring range flow w_N	0 … 10 / 20 / 40 / 60 m/s
Lower detection limit flow w_N	0.2 m/s (at T_M = 20 °C)
Measuring range temperature T_M	0 … +200 / +350 °C
Recovery time w_N	< 10 s (after temperature change of ∆ϑ = 40 K and at w_N = 5 m/s in air)
Operating temperature
Sensor head	0 … +200 / 0 … +350 °C (optional)
Electronics	-20 … +70 °C
Storage temperature	-20 … +85 °C
Material
Housing	Aluminium, anodised
Sensor tube	Stainless steel 1.4571
Sensor head	Platinum resistor element (glass-passivated), ceramics
Compression fitting	Stainless steel 1.4571 or brass (depending on sensor option)
Measuring accuracy
Standard w_N	± (3 % of measured value + [0.4 % of fmr; min. 0.08 m/s]) ¹⁾
High precision (optional) w_N	± (1 % of measured value + [0.4 % of fmr; min. 0.08 m/s]) ¹⁾
Response time (t₉₀) w_N	3 s (jump of w_N from 0 to 5 m/s in air)
Temperature gradient w_N	< 8 K/min (at w_N = 5 m/s in air)
Temperature T_M (w_N > 2 m/s)	± 2 K (T_M = 10 ... 30 °C) ± 4 K (in remaining measuring range)
General data
Humidity	Measuring mode: Non-condensing (< 95 % RH); high relative air humidity in combination with high temperature can cause measurement deviations
Operating pressure (max.)	Atmospheric (700 … 1,300 hPa) / 16 bar (optional; over pressure)
Display	4 x Duo-LEDs (green / red / orange)
Supply voltage	24 V DC ± 20 %
Current consumption	Typ. 50 mA (max. 250 mA)
Start up time	Approx. 10 s after switch-on
Analog outputs for w_N and T_M (type: Auto U / I)	Auto-U/I: 0 … 10 V / 4 … 20 mA (signal characteristic depends on R_L) Voltage output: R_L ≥ 550 Ω (short-circuit protected) Current output: R_L ≤ 500 Ω Change-over hysteresis: 50 Ω C_L ≤ 10 nF
Pulse outputs: Signalization	0 … 100 Hz or 1 impulse / m3 or free selectable frequency (10 … 100 Hz)
Pulse outputs: Technology	1. Highside-driver (open collector at protected supply voltage; not galvanically isolated) High level: > supply voltage - 3 V 2. Semiconductor relay (galvanically isolated), max. 30 V / 50 mA
Fieldbus (optional)	Profibus DP / DeviceNet
Electrical connection	Plug-in connector M12 (A-coded), male, 8-pole (shielded), screwed
Maximum cable length	Voltage interface: 15 m Current interface (pulse outputs): 100 m
Mounting position	Arbitrary (atmospheric; under higher pressure preferred horizontally)
Mounting tolerance	± 3° relative to flow direction
Type / class of protection	IP65 (housing), IP54 (probe) / III (SELV) or PELV (EN 50178)
Probe length	250 / 400 / 600 / 1,000 mm (for both: compact probe and remote probe)
Weight	550 g max. (400 mm input length) / 800 g (field bus version)
Cable length (remote version)	Selectable: 1 … 10 m (in steps of 1 m)

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

	Description	Article number
Basic sensor	SCHMIDT^® Flow Sensor SS 20.651	546650-	A	B	C	D	E	F	G	H	DD
	Options
	Standard		1
Output signals	Basic (2 x analogue auto-U/I plus 2 x impulse)			1
	Profibus DP-V0			2
	DeviceNet			3
Mechanical version	Basic (compact version with fixed probe)				1
	Remote version with cable length: _____ mm (1 ... 10 m)				2
	Probe length 250 mm					1
	Probe length 400 mm					2
	Probe length 600 mm					3
	Probe length 1,000 mm					4
Measuring range and adjustment	Measuring range 0 ... 2.5 m/s						1
	Measuring range 0 ... 10 m/s						2
	Measuring range 0 ... 20 m/s						3
	Measuring range 0 ... 40 m/s (only at H = 3 or 4)						4
	Measuring range 0 ... 60 m/s (only at H = 3 or 4)						5
	Standard adjustment							1
	Standard adjustment with factory calibration certificate							3
	High precision adjustment, including factory calibration certificate							2
Impulse output	Standard: w_N ~ f = 0 ... 100 Hz (w_{N, max} = f_max)								1
	1 Impulse/m³ for pipe diameter (round): _____ mm (min. 20 mm)								2
	Selectable f_max: _____ Hz (10 ... 100 Hz)								9
Temperature and pressure	200°C atmospheric									1
	200°C atmospheric (coated)									2
	200°C pressure-tight									3
	200°C pressure-tight (coated)									4
	350°C atmospheric									5
	350°C pressure-tight									6
	Pressure DD: ___ (00 ... 16 bar; 00 = atmospheric; > 1 bar overpressure)										00 16

Accessories

Connection technology

Description	Article-Number
Connecting cable 8-pin, length 5 m, with coupler socket and open cable ends	524 921
Coupler socket 8-pin, cable length selectable, (2 … 100 m; 1-m-steps), free of halogen, with cable end sleeves	524 942
Coupler socket 8-pin, with screw connections, for cable diameter ø 6 ... 8 mm	524 929
Power supply: out 24 V DC / 1 A; in 115 / 230 V AC (strip terminal)	535 282

Mounting and fixing technology

Description	Article-Number
Compression fitting SS 20.651 HT-p = 350 °C	525 734
Welding sleeve G½, steel, according to EN 10241, 5 pieces	524 916
Welding sleeve G½, stainless steel 1.4571, to EN 10241, 2 pieces	524 882
Assembly kit for pipe assembly suitable for MD 10.010/10.015, including pipe clamps and collar for adjustment for the pipe diameter	531 394

Measured value display

Description	Article-Number
LED display MD 10.010 in wall housing to show volume flow and flow velocity, 85 … 250 V AC and sensor power supply	527 320
LED display MD 10.010, similar to 527 320 but with 24 V DC voltage supply	528 240
LED display MD 10.015, similar to 527 320 but with an additional sum function and a second measuring input	527 330
LED display MD 10.015, similar to 527 330 but with 24 V DC voltage supply	528 250