SCHMIDT® Flow Sensor SS 20.515 LED

Thermal flow sensor with integrated electronics for measuring flow velocity of air, especially designed for monitoring laminar flow of air in cleanroom facilities.

Aerodynamically shaped dumbbell head with optimal flow properties, largely independent of direction
Cleanroom compatible design in accordance with GMP standard to prevent surface contamination
Operating status indication and serial number visible, even when sensor is installed
Flow and temperature signal
Probe length 300 … 1,000 mm (optional special length)
Probe length angled version: 150 / 270 mm x 300 mm
Measuring ranges 0 … 1 / 2.5 / 10 m/s
Vertical adjustment (for laminar flow applications, optional)
Coating (optional; sensor head only)
Cleanroom sensor

New: Now also in short design: 150 mm x 300 mm (angled)

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

Laminar flow monitoring in cleanrooms
Process control in pharmaceutical, semiconductor technology and food industry
Use in isolators, flow boxes and sterile filling machines

SCHMIDT Technology – Simply a question of better measurement

Specifications

Technical data
Measuring quantity	Standard flow velocity w_N based on standard conditions sup>1) Temperature of medium T_M
Measured medium	Air or nitrogen, other gases on request
Measuring range w_N	0 … 1 / 2.5 / 10 m/s
Lower detection limit w_N	0.06 m/s
Measuring range T_M	-20 … +70 °C
Measuring accuracy
Standard w_N	±(3 % of measured value + 0.05 m/s) ²⁾
High precision (optional) w_N	±(1 % of measured value + 0.04 m/s) ²⁾
Response time (t₉₀) w_N	3 s (jump from 0 to 5 m/s)
Temperature gradient w_N	< 2 K/min (at w_N = 5 m/s in air)
T_M (w_N > 1 m/s)	±1 K (10 … 30 °C); ±2 K (remaining measuring range)
Operating temperature
Sensor	-20 … +70 °C
Storage temperature	-20 … +85 °C
Material
Sensor head	PBT (glass-fibre reinforced), stainless steel 1.4571, protective coating (optional)
Sensor tube	Stainless steel 1.4404
Connector plug	Stainless steel 1.4404
Light ring	PC
General data
Humidity	Measuring mode: Non-condensing (< 95 % RH)
Operating pressure (max.)	Atmospheric (700 … 1,300 hPa)
Supply voltage	24 V DC ± 10 %
Current consumption	Typ. < 60 mA / max. 100 mA (signal currents included)
Analog outputs (w_N and T_M)	0 … 10 V (R_L > 10 kΩ; C_L ≤ 10 nF; short-circuit protected) 4 … 20 mA (R_L < 300 Ω; C_L ≤ 100 nF)
Error signal	Only current interface: 2 mA (according NAMUR NE43)
Electical connection	Connector M9, male, 7-pin (shielded), screwed
Maximum cable length	Voltage interface: 10 m; current interface: 100 m
Mounting position	Arbitrary (preferred in vertical down flow direction)
Protection type	IP65; electrical connector: IP67 (with correctly attached cable)
Protection class	III (SELV or PELV)
Probe length	Angled: 150/270 mm (vertical) x 300 mm (horizontal) Straight: Standard 300 mm; special length >300 … 1,000 mm (step: 10 mm)
Weight	300 g max. (straight, 1000 mm, type 3)

¹⁾ Standard conditions: T_N = 20 °C and p_N = 1,013.25 hPa

²⁾ Related to adjustment reference; "fmr" = final measuring range

Subject to technical change.

Order information

	Description	Article-Number
Basic sensor	SCHMIDT^® Flow Sensor SS 20.515	551 550 -	A	B	C	D	1	1	G	H	1
	Options
Mechanical type	Sensor length 150 mm x 300 mm		3
	Sensor length 270 mm x 300 mm		1
	Sensor length 300 mm (straight)		2
	Special length (only straight):	310 … 1,000 mm; 10 mm steps		9
Protection design	Without protective coating			1
Protection design	With protective coating (PU black; sensor head only)			2
Mechanical fixation	Threaded bushing M25 with lock nut				1
	Threaded bushing M25 with thread adapter M25 x 1,5 on PG21				2
	Threaded bushing M25 with shaft nut				3
	Welding bushing				4
	Flange bushing				5
	Without fixing material				6
Measuring ranges	Measuring range 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
	Measuring range 0 … 2.5 m/s					2
	Measuring range 0 … 10 m/s					3
Measuring direction	Unidirectional						1
Direction representation	Unidirectional							1
Output signals	0 … 10 V								1
Output signals	4 … 20 mA								2
Adjustment accuracy and calibration	Standard adjustment									1
	Standard adjustment unidirectional with factory calibration certificate									4
	High precision adjustment with factory calibration certificate									2
Sensor programming	Factory setting										1

Accessories

Connection technology

Description	Article-Number
Coupler socket, 7-pins, with soldering terminals for cable-Ø 0.14 mm2	535 278
Connecting cable with coupler socket, 7-pin, 5 m length, open cable ends, material PUR	535 279
Connection cable with coupler socket, 7-pin, length selectable (2 … 100 m; 1 m steps), open cable ends	505 911 - 4
Connecting cable with angled socket, 7-pin, 10 m length, open cable ends, material PUR	535 281
Power supply unit: output 24 V / 1A DC, supply voltage 115/230 V AC (strip terminal)	535 282

Mounting and fixing technology

Description	Article-Number
Assembly kit for pipe assembly suitable for 10.010 / 10.015, including pipe clamps and collar for adjustment to 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 … 230 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

Miscellaneous

Description	Article-Number
Calibrator MK 40.450 - Set (8 / 12 / 16 mA)	546 741-4
Attachable protective clip for dumbbell head against mechanical influence, (stainless steel)	531 026
Attachable protective 2-wires-clip for protection against mechanical influences, stainless steel, H₂O₂-resistant	559 124