DIGITEL controlled blower
DPA02
Low Volume Sampler (LVS)
for autonomous and continuous measurements
The DIGITEL blower DPA02 is a part of a system to sample dust and aerosol particles for later assessment and analysis. The sampler operation range in standard execution is 0,2 -1,2 litres per minute. The system’s usual designation is „Low Volume Sampler“.
For different applications different types of sampler are available. The current types are listet at the technical data .
Air-borne-dust parts in the sampled air are separated on to 47 mm diameter filters, DNPH tubes or the like. Sequent gravimetric and analytical analysis could be conducted depending upon the pollutants of interest. Filter material and structure selection (deep filters, porous filters, glass fibres, silica fibres, pulp, Teflon, porosity....) will depend on the analysis purpose. The filter conditioning is important in order to achieve reproducible results.
The DPA02 has a motor driven returnable valve with 16 ports. The magazine is convertible. Consequently the system is applicable for tubes of different sizes and diameters as well as those of different manufacturers.
A flow meter controls the selected air flow rate. This value should be calibrated first at the beginning of a measurement session, using a gasmeter or a secondary standard, e.g. an additional flow meter. During air sampling, the pump flow rate is dynamically controlled, so that this value is kept at good reproducibility and at long-term stability despite the deposited filter flow resistance and the sampled ambient air pressure / temperature variation.
An integrated microprocessor unit controls the filter changes at the exact preset time and collects all relevant data and events. Hereby the air quantity flowing through the filter is defined with high accuracy.
Diverse pre-separators
are available for the sampling concerning continuous and discontinuous
operation for variable flow rates and separation levels.
Various remote-control interfaces are built in for operation in automated
measurement networks.
The operating principle is schematically illustrated below.
1
Suction nipple
2 Pre-filter
3 Vacuum
pump closed
4 Filter
/ Baffle
6 Outlet
7 Infrared
photo cell
8 Control
electronic
9 Microprocessor
control
with
keyboard
and
LCD-Display
10 Pressure
/
Temperature
module
11 Motor
driven 16-way-valve
with
magazine for 16 tubes
12 Electric
supply line 230V
13 Main
switch
14 Net
filter/ power supply
15 PCMCIA
card 256 kByte
16 RS-232C
data logging/
remote
control
17 Temperature,
pressure and
humidity
sensor (optional)
18 Wind
data connection (optional)
Specifications of the programmable
blower DPA02 :
Speed controlled 12V DC motor.
Flow rate
regulation :
Continuous air flow rate by regulation of the suction power via flow meter
with photo electric floater sensor.
Flow rate readible on the precision-flow rate meter (calibrated by hand).
Desired value of the total flow rate zone continuously adjustable.
Display of the suction utilization.
Flow rate: 0,2 - 1,2 l/min.
Pressure
and temperature measurement of the air in the flow rate measurement system:
for each filter a correction factor will be issued (worked out of the
average temperature and the average pressure of the measuring air) On
the basis of this correction factor and the tuned flow rate the standard
volume for each filter can be calculated.
Controlling:
Microprocessor-controlling
Flow rate programs by dialog via key pad and LCD-display adjustable
Battery backed data memory
Handling time to program start programmable
RS-232C printer interface.
RS-232C interface for remote inquiry and remote control
At the use of a returnable valve each port is programmable
Manual operating possible.
Overload display and overload processing
Memory cards write -/read device for PCMCIA - cards.
The write/read device is able to read and write the memory cards PCMCIA/JEIDA4
of the compatible 68-Pin - Format. The write/read device is connected
internally at the data bus.
Sampling:
motor driven 16-way-valve.
sealing cap for transport.
all parts of ematalised
aluminium.