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Chlorine Analyzers -Swan Codes II
Swan in Indonesia supplies the Codes II for the measurement of free chlorine, total chlorine, hypochlorous acid, chlorine dioxide, ozone and monochloroamine. This instrument uses the DPD colorimetric method based on APHA method 4500 CI-G and EN ISO 7393-2. The DPD reacts with chlorine to give a colour development. The intensity of this colour is measured by a photometer and this gives the quantity of chlorine dissolved in the water. The DPD method is a very accurate method and gives repeatable reading at low levels. The equipment is supplied complete with measurement and control electronics, photometer, flow indicator, reaction chamber, reagent dosing system and reagent containers. Integrated pH and temperature measurement is available as an option for compensation. All usual dosing devices for disinfectants and pH control can be connected through relays or analogue output signals. A third signal output is selectable as a current output. interface is RS485 profibus or Modbus. Two independent controllers can operate simultaneously. A chemical cleaning module is available separately. Download of logged data is possible with hyper terminal. The range is 0-5ppm with a cycle time of 1-12 mins.
Amperometric chlorine analyzers without the use of chemicals is also available see analyzers for ultra pure water.
Online turbidity meter – Swan AMI Turbiwell
Arasains Indonesia supplies the Swan AMI Turbiwell for high precision measurement of turbidity in treated water. The range is 0.00 to 100 NTU with a precision of 0.003 NTU. This analyser is a non contact nephelometer which means that the sensor is above the water level. This will ensure that the sensor will not be affected by accumulation of coagulants thus ensuring stable reading over long time. There is an optional degasser through which all incoming water have to pass through. As the water flows through the circular tortuous path any bubbles will be eliminated. Bubbles have a large interfering effect in turbidity readings and must be removed for accurate readings. The Swan Turbiwell comes complete in a mounting panel and is ready for use. Calibration is by use of Formazine standards. The measuring and control transmitter is in an IP66 aluminium case. There are two signal outputs freely scalable and a potential free alarm contact as a summary alarm for programmable alarm values, for instrument faults and monitoring of maintenance requirements.
Online fluoride analyser Swan AMI ISE
Flouride is often added to drinking water for dental health. However too much fluoride can actually cause damage to teeth. Therefore the control of fluoride is very essential. The Swan fluoride analyser measures fluoride by means of an ion selective electrode. There is no reagent used in this measurement. A spray nozzle for sensor cleaning is optional. The range is 0.1 to 1000 ppm.
Distribution Water Monitoring – Horiba TW100
It is of interest to monitor on line, the quality of water in the distribution network. The water quality usually leaves the treatment plant in good condition but very often at the consumer side the quality may not meet standards. This can be due to reduction in the strength of chemicals like chlorine which reacts with organics or due to infiltration. Arasains Indonesia supplies the Horiba TW100 multi parameter analyser to monitor the condition of water in the distribution system. Parameters monitored are turbidity, color, free chlorine and pressure. Three more parameters are available as an option; pH, conductivity and temperature. No reagents are required for these measurements thus ensuring low maintenance. Turbidity is measured by absorbance method, chlorine by polarography, pH by glass electrode. This is a compact system that can be installed easily anywhere with its own solar power source. Remote communications by GSM is optional.
FREQUENTLY ASKED QUESTIONS
Why is the turbidity measurement in a water treatment plant so difficult?
Turbidity is an indication of the impurity of water. It suggests that the water is unfit for drinking. Usually turbidity is measured from 1-5 NTU but usually a good treatment plant can produce water at less than 1 NTU. This makes the measurement of turbidity difficult because it is close to zero. Interference by air bubbles in water or by coagulants sticking to the measuring cell will cause problems if not eliminated by the instrument design. A truly reliable analyser for turbidity is needed as it is the most important parameter in a water treatment plant.
Which is the best method to measure chlorine in water?
the best method to measure chlorine in a water treatment plant is the DPD method. This method is good for the low levels of chlorine encountered in the water treatment plant. During each measurement the instrument is zeroed and thus there is no drift. The other method is amperometric which suffers from drift and stray currents.
Is it necessary to measure fluoride on line or is a lab measurement once a shift is sufficient?
Fluoride when present in too large a quantity actually destroys teeth. On line monitoring is of utmost importance because upsets in dosing can happen. Only online monitoring can prevent the dangerous overdose of fluoride.
For more information on the above tests contact the friendly Arasains sales staff or fill in the enquiry form.
For more questions ask Dr Lee
Caution : not all question can or will be answered