Dissolved Oxygen
Measurement and Control
4283
Measuring range Dissolved oxygen 0 to 20.0 ppm or mg/l - 0 to 200% SAT Resolution 0.1 ppm or mg/l - 1% SAT
Dual parameter versions available 4238-83 [pH/REDOX - Dissolved oxygen] 4262-83 [Turbidity - Dissolved oxygen] 4263-83 [Suspended solids - Dissolved oxygen] 4283-83 [Dissolved oxygen - Dissolved oxygen] with S423/C/OPT optical sensor only
S423/OXYSENS™ Main measuring range
The oxygen contained in the liquids is measured using the so-called Clark cell system. These cells generate a current proportional to the partial pressure of the oxygen, which can be detected using a suitable signal converter. In order to prevent interference during measuring, the Clark cell is protected by a gas-permeable membrane. The membranes typically used are made from PTFE but, as this material is mechanically fragile, frequent changing is often necessary, along with the related “demanding” operations (interruption of measurement, replacement of the electrolyte, regeneration of the electrodes). The S423 solves this problem by using a membrane made from OPTIFLOW™. Manufactured as a sheet around a layer of steel, it is very stable mechanically and very resistant to chemically aggressive environments as well as high pressure. Thanks to the special construction of the measuring electrodes, this system also makes the sensor totally “maintenance free”.
Maintenance
OXYSENS™ sensors are maintenance-free, and do not require the replacement of the membrane, electrolyte or regeneration of the electrodes, to measure the oxygen in aqueous samples. Typical applications include water treatment plants and the fish industry.
Technical data Electrode material Electrolyte Membrane
Silver-platinum combination Alkaline solution OPTIFLOW™
Temperature sensor
NTC 22 kOhm
Polarisation current
-670 +/- 50 mV
Sensitivity Stabilisation time Operating temperature
40 ... 80 nA at 25 °C in air typical 15 min., max. 1 h 0 ... 60 °C
Construction materials
1.4435 stainless steel, PEEK, silicone, NBR
Regeneration
not required
Response time t98%
max. 60 s at 25 °C, from air to nitrogen
Temperature response
approx. 3.1%/K
Measuring liquid speed
min. 0.03 m/s
Influence of flow rate
< 5% at 25°C
Oxygen consumption
approx. 20 ng/h in air at 25 °C
Storage temperature
-10 ... 60 °C, with water inside the protective cap
Residual current
< 0.5% current in air
Pressure
0 ... 4 bar during insertion; max. 0.5 bar in total during submersion
Zero drift
< 0.5% current in air every 2 months at 25°C or in water in stable conditions
Outer diameter Connection
12 mm PG 13.5 – threaded
Sensitivity drift
< 10% every 2 months at 25°C in water in stable conditions
4Optical technology: no membrane or electrolyte 4No signal drift: no calibration 4Digital output: Modbus RS-485 4Sturdy stainless steel structure Fields of application
• Biological purification systems (aeration, nitrification/denitrification tanks etc.) • Industrial water treatment plants • Monitoring surface water • Aquaculture • Water conditioning
Optical technology
The S432/C/OPT sensor measures oxygen with a built-in temperature probe. The measuring technique is based on the optical principle: a diode emits a light blue towards a support on which a fluorescent substrate is applied. The substrate initially reacts by emitting a red light (luminescence), then returns to its initial state. The intensity of the red light produced and the rate of return to the initial state are related to the concentration of oxygen present. This innovative method ensures reliable, accurate measurements with no drift over time, therefore system calibration is no longer necessary. No maintenance is required except for replacing the luminescent support about every two years. The system does not consume oxygen, therefore it is suitable for the most varied fields of application, including those in which the measuring liquid is almost stationary.
Digital technology
Built-in pre-amplification circuit and digital signal processing. The S432/C/OPT sensor saves the calibration data for optimal data management. The output signal is provided on the RS 485 serial port.
Physical characteristics
Compact, sturdy and lightweight, the stainless steel body enables fixed or portable applications.
Technical data Measuring principle Measuring ranges
Membrane
Interchangeable sensor cap Typical duration 2 years.
Electrodes
No electrode
Electrolyte
No electrolyte
Dimensions
Diameter: 34 mm Length: 180 mm Fitting: 3/4" male
via NTC
Weight
850 g (sensor + 10 m cable)
90% of the actual value in less than
Materials in contact with the liquid
Stainless steel 316L/PVC
Maximum operating pressure
5 bar
Protection rating
IP68
Storage temperature
-10….. + 60°C
Optical by means of luminescence 0,00…20,00ppm / 0-200 % Sat 0…50°C
Resolution
0,01 ppm
Precision
+/-0,1ppm / +/-1 %
Temperature compensation Response time
60 seconds Liquid stirring speed
Not required
Digital interface
RS-485 Modbus
Maximum refresh time
< 1 second
Measurement and Control
S432/C/OPT Oxygen and temperature sensor with OPTICAL technology
Measurement and Control
42 series The 42 series developed by Chemitec is dedicated to the water treatment and industry sectors, and enables the following parameters to be measured: 4pH/REDOX 4Dissolved oxygen 4Conductivity 4Turbidity 4Suspended solids 4Chlorine 4Chlorine dioxide 4Ozone
Process control device Display 4Simultaneous measurement (numerical and bar graph) and temperature values. 4Scrolling output values. 4Graphic icons for: status of digital outputs, washing cycle, data recording, alarms. 4Possibility to display the measurement only in large format.
Data recording 44-bit internal flash memory (about 16,000 records). 4Recording interval: 1 to 99 min. 4Type: Circular (F.I.F.O.) or filling. 4Ability to view the logged data in table or graphic form, with indication of the maximum, minimum and average values in the selected periods. Wall-mounted version with IP66 protection rating (144 x 144 x 120 mm)
PID control 4P - PI - PID functions activated on the analogue or digital output. 4Proportional range: 0 to 500%. 4Integral time: 0:00 to 5:00 min. 4Derivative time: 0:00 to 5:00 min.
2 analogue outputs 4Output 1 programmable for measurement. Panel-mounted version (144 x 144 x 100 mm)
4Output 2 programmable for measurement / temperature / PID control. 4 The limits of the outputs are freely programmable within the measuring range.
4 digital outputs 4ON/OFF set point: Programming the operating range (hysteresis/direction) and start/stop time 000 to 999 seconds. 4PID control: Pulses, frequency or PWM (2 set points).
RS485 serial port
4Programmable for: tool faults, minimum, maximum, set point delay, stay time (live check).
4For set-up and remote real time acquisition or for downloading data (using dedicated software).
4Delay time: 00:00 to 59:59 mm:ss with minimum interval of 15 sec.
4 MODBUS RTU communication protocol.
4Stay time 00:00 to 99:59 hh:mm
USB port
4Set point deactivation (in case of alarm): Enabling/Disabling.
4USB for direct download on PEN DRIVE (optional).
Washing electrodes
Manual controls
4Programming the interval (minimum 15 min) and the duration.
4Possibility to simulate the analogue and digital outputs from the keypad.
4During washing, all the analogue and digital outputs are frozen.
Temperature compensation
Digital input
4Using PT100 sensor with 3 or 4 wires, or PT 1000.
4To disable the doses.
Electrical connections
Input Measure Input Temperature
Serial Port RS485
1
1st Channel
Serial Port RS485
8
2
2nd Channel
Vac/dc Input
3
USB port
Digital Input
4
Output 4÷20 mA
CPU Power Supply
100÷240 Vac
Ground
9
Output 4÷20 mA
5
2nd Channel
6
Keypad
7 Graphic display
1st Channel
NO
Relay 1 Setpoint
NO
Relay 2 Setpoint
10 NO
Relay
Alarm/Temp1
NO
Relay
Alarm/Temp2
Input 1 Measurement 2 Temperature 3 15 - 30 VAC-VDC input 4 Digital input 5 Universal power supply 100 – 240 VAC
6 Ground 7 Keypad and graphic display
Output 8 RS485 serial port and USB 9 Current outputs 10 Digital outputs • • • •
Set Point 1 Set Point 2 Alarm /Temp 1 Washing / Temp 2
Measurement and Control
Alarm
Measurement and Control
Simple and intuitive software
4Interactive, easy to read interface
4Main menu with graphic icons
Display of stored data in graphical form, even during RUN TIME measurement
MODBUS RTU serial interface for: 4Communication of data in real time 4Downloading the data stored on PC via SW or directly on the removable USB pen drive (optional)
Measurement and Control
Dimensioni Wall-mounted version with IP66 protection rating 122,5 144
32
80
16.25
144
Ø6.5
68
25.5
4 x pg9
38
18
38
30
2 x pg11
35
35
Panel-mounted version 144 x 144
Panel-mounted version 96 x 96
96
88
92
92
108
7
123
Paab Tekno Trading AB - Tingvallastrand 12, 661 40 Säffle, Sweden Tel: +46 533 150 60 - Fax +46 533 169 31 -
[email protected] - www.paab.com
