- What is the application?
ChemScan® publishes a number of Application Summaries that contain a discussion of standard applications for potable water, municipal wastewater and industrial use. If an application is not listed, ChemScan® products may be able to be used, but additional information or samples may be needed. Contact ChemScan or your local ChemScan® representative for additional information.
- Which parameters should be monitored?
You may be able to find the parameter listed on the ChemScan® Parameter List. This list shows the types of applications, the analysis method and the specific ChemScan® analyzers that are capable of monitoring a given parameter. Note that if only one or two parameters are required, the UV-2150 or UV-3150 may be preferred. Multiple parameters using both primary analysis and secondary analysis may require a UV-4100 or UV-6101 which have more capabilities but are also more expensive.
- How many sample points should be monitored?
This will depend on the details of your process, including the control strategy to be used, the number and arrangement of process vessels, the arrangement of parallel flow paths and distances from each proposed sample point to the analyzer. Some ChemScan® analyzers can handle as many as eight incoming sample lines, which can greatly reduce the cost of analysis for each parameter at each sample point if the distances for sample line piping and pumping are not prohibitive.
- What are the sample characteristics at each point?
Solids and turbidity are the major issues. If the samples will have high (150 mg/l or more) of suspended solids or high (60 NTU or more) of turbidity, filtration of the sample will be required prior to analysis. ChemScan® has a number of sample handling accessories available including motor operated valves, high capacity sample pumps, cross flow ultrafilters and sample sequence controllers. A single pump and filter system can be used for up to eight sample points, controlled using special valves connected to the external controller. Sample analysis intervals, piping layout, pipe diameter, head loss and other factors must be custom engineered for each project. Contact ChemScan for assistance.
If the samples will have low solids and turbidity (the usual case for most potable water and wastewater effluent samples) no filtration is required, but samples will need to be pumped to the vicinity of the analyzer or the analyzer will need to be located close to the sample point to be monitored.
- What concentration range and accuracy is expected for each parameter at each sample point?
Unlike other types of analyzers that provide a rigid minimum and maximum concentration range, take it or leave it, ChemScan® analyzers can be calibrated to detect each parameter over a range that is appropriate for each sample point. This is because ChemScan® uses a combination of factory and field calibration techniques and provides individual attention to the set up and calibration of each analyzer at every site. If the same parameter is being monitored by one ChemScan® analyzer at multiple sample points, the use of an individual range for each sample point may be possible, although each range is considered to be a separate parameter. Each ChemScan® analyzer has a maximum number of parameters that are able to be analyzed.
- What type of data communication is desired?
All ChemScan® analyzers have a backlit LCD display on the front of the instrument which will sequence through the last measured value for each parameter at each sample point. All ChemScan® analyzers have an internal data log which records the last 1,000 cycles for each parameter and sample point, up to a total of eight values. Certain maintenance logs are also recorded. All logs can be downloaded from the instrument using special software available from ChemScan.
Each ChemScan® analyzer has the additional capability to provide a 4-20 mA output for each parameter at each sample point, up to a maximum number of outputs for each product.
Where sample point selection is controlled by a ChemScan® Sample Sequence Controller, analog or serial outputs are available from the controller, up to a maximum of 16 analogs. There is no limit on the number of serial outputs, although additional charges may apply for special formats. Contact ChemScan or your local representative for a list of data communication formats available.
ChemScan® also has alarm output capabilities. See product specifications for the type and number of alarm outputs available for each product.
ChemScan® Process Analyzers do not provide control signal outputs, but can be configured to communicate with controllers or other external devices that provide process control calculations and signals. Although sample sequences and analysis intervals are typically controlled by ChemScan, the analyzers can be configured to initiate an analysis sequence under the control of an external device. Contact ChemScan for details.
- Where will the instrument be located?
ChemScan® prefers a sheltered location, out of direct sunlight, with ambient temperature always above freezing and always less than 105°F (35°C).
All instruments can be either stand mounted or wall mounted using Unistrut.
ChemScan® instruments generally require a dedicated branch circuit free from power surges or dips. 110V, 60 cycle power is standard. All systems will require an open drain line in close proximity to the analyzers. Sample line location and pressure will affect analyzer configuration.