Schmidt SS 20.600 User manual

SCHMIDT®Flow Sensor
SS 20.600
Quick Guide

Quick Guide –SCHMIDT®Flow Sensor SS 20.600 Page 2
SCHMIDT®Flow Sensor SS 20.600
Table of Contents
1Important information.......................................................................2
2Application range.............................................................................2
3Assembly.........................................................................................2
4Electrical connection........................................................................2
5Commissioning................................................................................2
6Calculation of volume flow...............................................................2
Imprint:
Copyright 2022 SCHMIDT Technology GmbH
All rights reserved
Version: 536020.02D
Subject to modifications

Quick Guide –SCHMIDT®Flow Sensor SS 20.600 Page 3
1 Important information
This quick guide must be read completely and observed carefully, be-
fore putting the unit into operation.
For detailed information on mounting and operation of the sensor,
a comprehensive manual (535084.02) is available at:
www.schmidt-sensors.com or www.schmidttechnology.de
In case of doubt, please observe the information given there.
Any claims under the manufacturer's liability for damage resulting from
non-observance or non-compliance with these instructions will become
void.
Tampering with the device in any way whatsoever - with the exception
of the designated use and the operations described - will forfeit any
warranty and exclude any liability.
The unit is designed exclusively for the use described below (refer to
chapter 2). In particular, it is not designed for direct or indirect protection
of personal or machinery.
SCHMIDT Technology cannot give any warranty as to its suitability for
a certain purpose and cannot be held liable for accidental or sequential
damage in connection with the delivery, performance or use of this unit.
2 Application range
The SCHMIDT®Flow Sensor SS 20.600 is designed for stationary meas-
urement of flow velocity as well as the temperature of air and gases.
The sensor measures the normal velocity wN(unit: m/s), based on normal
conditions of 1013.25 hPa and 20 °C. The output signal is linear and in-
dependent from pressure and temperature of the medium to be measured.
When using the sensor outdoors, it must be protected against di-
rect exposure to the weather.
When using the sensor in ATEX areas the Supplementary in-
structions for use in explosive atmosphere ATEX (535689.02)
must be read and observed carefully.
Information and safety instructions for the use in media having an
oxygen percentage of > 21 % can be found in the general Instruc-
tions for Use (535084.02).

Quick Guide –SCHMIDT®Flow Sensor SS 20.600 Page 4
3 Assembly
Position the sensor head always at the most advantageous posi-
tion for flow measurement, typically in the middle of the pipe.
The sensor measures unidirectional, the axial tilting of the sensor
head relative to flow direction should not exceed ±3°
The sensor should preferably be installed in hor-
izontal pipes.
Installation in a vertical pipe with downward flow
should be avoided, as the lower measuring range
limit will be increased.
In case of a downward flow at 16 bar overpres-
sure, correct measurement values will be given at
a flow velocity above 2 m/s.
Correct measurements require a flow low in turbulence.
This can be achieved by providing sufficiently long and straight distances
without flow disturbing structures in front of and behind the sensor.
The minimum run-in (L1) and run-out (L2) distances are defined by the
type of the flow obstacle upstream of the measuring position and the
inner pipe diameter D.
Flow obstacle upstream of measuring distance
Minimum distance length of
Run-in (L1)
Run-out (L2)
Light bend (< 90°)
10 x D
5 x D
Reduction / expansion / 90° bend or T-junction
15 x D
5 x D
Two 90° bends in one plane (2-dimensional)
20 x D
5 x D
Two 90° bends (3-dimensional change in direction)
35 x D
5 x D
Shut-off valve
45 x D
5 x D
wN < 2 m/s
Flow

Quick Guide –SCHMIDT®Flow Sensor SS 20.600 Page 5
Installation
The sensor may only be mounted and dismounted when no pres-
sure is applied.

Quick Guide –SCHMIDT®Flow Sensor SS 20.600 Page 6
In case of mechanical strain (e.g. vibration), the nut of the com-
pression fitting must be secured additionally (e.g. a screw lock).
The alignment surface of the sensor’s enclosure must not be used
for countering.
Before pressurisation, the pressure-tight assembly as well as the
correct fastening of the compression fitting and the discarding
protection must be checked.
This check must be repeated periodically.
If the sensor head is immersed in water and operated under pres-
sure, the sensor may be damaged irreversibly.
The sensor measures unidirectional, the axial tilting of its head
relative to flow direction should not exceed ±3°.
4 Electrical connection
Make sure that no operating voltage is active during electrical in-
stallation and that the operating voltage cannot be switched on
inadvertently.
View on plug-in connector of sensor
To operate the sensor a supply voltage of 24 VDC ± 20 % with a
minimum current1of 200 mA is required.
The appropriate protection class III (SELV) respective PELV (ac-
cording EN 50178) has to be considered.
The specified wire colors are valid when one of the SCHMIDT®connect-
ing cables is used.
1
Without signal current of pulse output 2 (relay).
2
8 7
6
5
4
3
1
A / V
0 ... 100 Hz
Pulse/m³
 100 mA
A / V4 ... 20 mA
0 ... 10 V
0 ... 100 Hz
Pulse/m³
WH
BN
YE
GN
GY
PK
BU
RD  30 VDC
 21 VAC
 50 mA
24 VDC
±20 %
TMwN
AGND
GND

Quick Guide –SCHMIDT®Flow Sensor SS 20.600 Page 7
Pin
Name
Function
Wire colour
1
Pulse 1
Output signal: Flow velocity / volume (digital: PNP)2
White (WH)
2
UB
Operating voltage: 24 VDC ± 20 %
Brown (BN)
3
Analog TM
Output signal: Temperature of medium (Auto-U/I)
Green (GN)
4
Analog wN
Output signal: Flow velocity (analog: Auto-U/I)
Yellow (YE)
5
AGND
Reference potential for analog outputs
Gray (GY)
6
Pulse 2
Output signal: Flow velocity / volume (digital: Relay)3
Pink (PK)
7
GND
Operating voltage: Ground
Blue (BU)
8
Pulse 2
Output signal: Flow velocity / volume (digital: Relay)3
Red (RD)
Table 1
Typically, AGND has to be selected as measuring reference potential for
the signal output to avoid problems with mass offset.
Depending on the value of the connected load resistance RL, each analog
output switches between operation as voltage interface “U” (0 …10 V) or
current interface “I” (4 …20 mA) automatically (“Auto-U/I”).
The switching threshold is set by a load resistance of RL= 500 … 550 Ω
(hysterisis = 50 ), the maximum load capacity is 10 nF.
For voltage mode, a load resistance of at least 10 kΩis recommended.
5 Commissioning
The valid measuring ranges and the configuration of the signal outputs are
specified on the rating plate.
After applying the supply voltage, the sensor signals the initialization of
the measuring operation by means of all four LEDs (sequence: red, or-
ange, green). The flow output signal will at first adopt a higher value and
then settle to the correct measurement value after about 10 seconds.
LEDs flashing in red indicate an error. For detailed error description,
please refer to the general Instructions for Use (535084.02, page 25).
6 Calculation of volume flow
SCHMIDT Technology provides a "flow calculator" on its homepage for
the calculation of flow velocity or volume flow in (circular) pipes or (rectan-
gular) shafts for the different sensor types:
www.schmidt-sensors.com or www.schmidttechnology.de
2
Highside driver (galvanically not isolatied; current limited to 100 mA; load to GND)
3
Galvanically decoupled (max. 30 VDC / 21 VAC / 50 mA)

Quick Guide –SCHMIDT®Flow Sensor SS 20.600 Page 8
SCHMIDT Technology GmbH
Feldbergstrasse 1
78112 St. Georgen
Germany
Phone [phone] / 899-0
Fax [phone] / 899-101
Email [e-mail]
URL www.schmidt-sensors.com
www.schmidttechnology.de