Introduction; Description; Training; Location And Function Of Main Components - ABB 8232 Instruction Manual

1 INTRODUCTION

1.1 Description

The Model 8232 Ammonia Monitor is a microprocessor based
analyser using an ABB ammonia ion-selective probe. This
equipment is used for environmental water monitoring.

1.2 Training

Due to the specialised nature of the above instrument, it is
recommended that, where the end users personnel have had
no previous experience of maintaining this equipment, training
be provided by this Company.
Such training is available via the local Company in the UK, or
Overseas Agent elsewhere and may be carried out either on
the users premises or at the factory.
1.3 Location and Function of Main Components –
Fig. 1.1
Monitoring of any sample by ion-selective electrodes usually
requires certain conditioning to be performed on the sample to
allow accurate, trouble-free measurement. Such conditioning
involves regulating flow, controlling temperature and adjusting
chemical composition prior to presentation of the sample to
the point of measurement. This monitor carries out these
adjustments for each parameter in simple and easily
Microprocessor
Unit
Solenoid Valves
(behind case)
Push-to-Release
Latch
Hinged Door
2
Hinged Case
Calibration Constant Head Unit
Solution (behind case)
Containers with Sample Inlet and
Drain Connections
Fig. 1.1 Location of Instrument Components
understood steps. The sample is presented from the user's
pipework to a constant head unit and any excess is allowed to
overflow. This allows sample, under controlled pressure
conditions, to be presented to a multi-channel peristaltic pump
which proportions sample and reagent solutions through the
monitor to the mixing point. The resulting combined solution is
then temperature controlled to remove the effects of sample
and ambient temperature variations. The conditioned solution
is then delivered to the probe, under constantly flowing
conditions, where the ion measurement takes place.
The probe generates a millivolt output which is proportional to
the ion concentration. This output is processed by the
microprocessor-based electronics section to calculate the
actual sample concentration.
To maintain optimum measurement accuracy it is necessary to
introduce standard solutions of known concentration for
calibration purposes. The monitor utilises solenoid valves to
introduce these standard
predetermined intervals,
microprocessor.
The electronics section consists of the main Microprocessor
Unit situated at the top left and a User Junction Box at the top
right behind the hinged case.
Peristaltic
Pump
(cover removed)
solutions automatically,
under the control of
Case Lock
Cable Entry Glands
User Junction Box
(behind case)
Ammonia Probe
Case Lock
Temperature
Controlled
Block
at
the