Product Selection Guide
Which ChemScan® product is best for an application?
For most applications the critical factors are:
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
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
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
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.