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The all new ProAm analyser for the determination of ammoniacal-nitrogen
was officially launched at the IWEX exhibition in Birmingham, November
2003. The instrument received considerable interest from prospective
end users for its simplicity and the innovative measuring technique
which underpins its design.
The instrument has undergone extensive in-house and field testing
since its original development earlier in the year. A number of
units have already been sold and installed at key customer sites.
Based on current feedback we anticipate that this instrument is
set to establish itself as the preferred instrument for several
UK water companies. The units installed industry applications have
also given un-paralleled operational and measurement reliability.
Key advantages include:-
• Compact design using a proven technique
• No filtration typically required due to large tubing & pinch
valve technology
• Automatic cleaning as standard, improves reliability
• Simple user friendly operation
• Low detection limit (0.05ppm)
• Low capital and running costs
• Minimum maintenance requirements
The analyser comprises of an Ion Selective Electrode (ISE), reaction
vessel, peristaltic pump unit and microprocessor controlling electronics.
The sensor is a gas sensitive electrode used to report ammoniacal-nitrogen
concentration in liquids. A reagent is added to the sample and the
ammonium is converted to ammonia which diffuses through the electrode’s
membrane. The electrode potential changes logarithmically according
to the level of ammonia in the sample.
The standard instrument can be ranged from 0-1ppm to 0-500ppm as
required with special applications up to 1,000ppm. Calibration takes
place at two points, low and high. The calibration sequence is used
to validate measurement performance and alarm an unacceptable response
from the electrode.
The detected concentration is displayed locally on the instrument’s
LCD and can also be connected to telemetry. In addition to the analogue
4-20mA output, there are two user programmable alarm set points
as well as two utility alarm relays. These may be configured for
the loss of sample/calibration/reagent/wash solutions and poor probe
sensitivity. A fourth relay can be assigned for either no sample
or an off-line alarm (to indicate when the instrument is calibrating
or cleaning). Other communication protocols are also being developed.
The instrument is designed to run as an automatic analyser but manual
intervention may be initiated from the tactile keypad. The ProAm
is typically configured for continuous measurement but intermittent
analysis may also be programmed to further conserve reagents.
Typically, the analyser is installed to sample from a fast sample
loop without the need for pre-filtration. For some applications,
it is possible to use the internal peristaltic sample pump to deliver
the sample direct from source, further saving on installation and
running costs. The analyser requires a frost protected environment
to preserve the reagents and if a suitable building is not locally
available then only a small engineered secondary enclosure is required
to house the compact analyser.
Pollution & Process Monitoring Ltd
Bourne Enterprise Centre
Borough Green
Sevenoaks
Kent TN15 8DG
Tel: +44 (0) 1773 717318
Fax:+44 (0) 1732 780190
E-mail:  TOC@pollution-ppm.co.uk |
