ON- LINE ANALIZERS
PROCESS INSTRUMENTS, GRUNDFOS, MULTISENSOR and HACH LANGE analyzers include high precision sensors for immersion or pipe insertion. Process control in areas such as water treatment, environmental parameters monitoring, food and beverage production, wastewater treatment can only be achieved through on-line monitoring. The construction of the sensors allows long-term operation with minimal maintenance. The list of parameters includes: turbidity, suspended solids, disinfectants (Cl2, ClO2, O3, I2, Br2, PAA), trihalomethanes (THM), conductivity, dissolved oxygen, temperature, hardness, alkalinity, acidity, silica, chloride, salinity , phosphate, ammonium, nitrate, nitrite, iron, hydrazine, pH, redox potential (ORP), content of organic substances, COD, total organic carbon (TOC ), volatile organic compounds (VOC), pressure, level, flow, etc. Measuring controllers are designed for the connection of a single or multiple, up to 12 sensors. Besides displaying the measuring parameter, on-line controllers also provide local loops of automation using limit value, proportional control, PID or continuous control settings. Direct command for various actuators (pumps, solenoid valves, etc.) are available through analog output or relay. Via their digital interface on-line analyzers can be integrated into SCADA control systems. In field applications access to analyzer menus is possible via GSM modem, both for downloading data, for diagnostic or for modifying settings.
OPEN CHANEL FLOWMETERS
Open chanel flowmeters are suitable for mounting to any channel or underground pipe with gravitational flow. The most common application is metering of wastewater quantities, both at discharge into natural receivers or at the discharge of industrial users into sewerage systems. Monitoring and management of municipal sewerage systems has a useful tool in open chanel flowmeters, especially considering locations where household and industrial wastewater are collected in the same channels with rainwater. Supervision of water quantities in power plants as well as in irrigation are other very important applications, especially in conditions of strict management, e.g. imposed in times of dryness.
The operating principle is based on the most simple flow formula:
FLOW = AREA x VELOCITY
Level measurement is achieved by means of an ultrasonic sensor, whereas velocity measurement is done either by immersed Doppler sensor or by a Radar fixed above the channel. Both variants "scan" the entire wetted section of the channel calculating an average velocity. The measuring of flow velocity eliminates the need for primary transducer used in traditional systems as a hydraulic resistance (overflow weir , Parshall or Venturi channel, etc.).
AUTOMATIC WATER SAMPLERS
HACH-SIGMA and EFCON automatic water samplers are mainly used for supplying representative samples for laboratory tests in process control, also for inspection bodies and environmental studies.
Fixed and portable automatic water samplers fulfill several important requirements:
- ensuring a representative sample depends among others on the sampling frequency tracing the evolution of water quality over time,
- it is also extremely important the location and depth chosen for sampling.
These devices are microprocessor controlled and operate based on sampling programs.
Average as well as discrete samples can be collected on a given time interval and volume program. One can also perform flow proportional sampling by connecting the sampler to an external flowmeters signal. Different configurations are possible for containers: from one to 24 bottles with different capacities.
The HACH-SIGMA and EFCON samplers can be placed in the field due to construction materials that resist to a temperature range between -25C .... + 40C. A microprocessor controlled thermoregulation system (heating and cooling) maintains 4C temperature in the insulated inner chamber of the samplers, as required in microbiology standards.