Toxicity-Monitor

cluering at aol.com cluering at aol.com
Wed Nov 27 14:38:41 EST 1996


The 1-Hz-Fluorescence-Toximeter:

An apparatus for fast and sensitive detection of toxic substances in
water.

The 1-Hz-Fluorescence-Toximeter continually determines toxic substances in
water. Algae for the tests are automatically and independently cultivated.
These standardised algae are added to the water sample and the active
chlorophyll concentration is analysed. If the algae are damaged, e.g.
through herbicides which reduce the concentration of active algae, an
alarm is induced. Additionally the 1-Hz fluorescence-toximeter operates as
an instrument for the exact measurement of algae content in water. This
measurement corresponds to that of the bbe 1-Hz fluorimeter 42A03.

Construction of the 1-Hz-Fluorescence-Toximeter:
The cultivation of the algae takes place in a fermenter which is regulated
"turbidostatically" by a second 1Hz-fluorescence measurement. Due to this
regulation the algae concentration is kept in a steady state. For the
measurement water samples are continually pumped through the 1-Hz
fluorometer where the algae concentration is determined. After which a
precisely defined amount of algae is injected into the 1-Hz fluorometer.
The concentration of the additional living algae stays constant as long as
no toxic substances are present. The presence of toxic substances reduces
the concentration of the additional algae.

In order to clean the measuring unit a salt solution is pumped into it
after the measurement. This also hinders the growth of algae in the unit.
The salt solution is reused so as to minimise the consumption. The hoses
of the 1-Hz fluorometer-toximeter are rinsed with the salt solution at
certain intervals so as to stop the growth of algae here as well. The
rinsing rate is adjustable.

Software for analysis:
For the analysis of the results the bbe Dynsprung program is used. It has
already been installed in numerous toximeters. Dynsprung notices jumps -
and therefore also the toxic events - when the measuring results are still
in a blurred state and then increases the sensitivity. 

Measurements:
- Measurement of direct chlorophyll fluorescence:
This measurement corresponds to the wet-chemical chlorophyll analysis. 
- Measurement of living chlorophyll fluorescence of the water sample
(1-Hz-method):
This measurement shows the percent of active chlorophyll and serves as a
toxicity measurement.
- Measuring the transmission of the sample:
This measurement takes place automatically during each analysis so as to
compensate the influence of substances which cause turbidity.

Advantages of the 1Hz-Fluoreszenz-Toximeter:
  high sensitivity
  independent cultivation of algae
  cultivation control due to the living chlorophyll measurement
  no dosage mistake through ageing hoses
  automatic cleansing of the measuring unit and the hoses
  reutilization of the cleansing solution
  no loss of time through the alarm induction
  auto-start after current failure
  battery-buffered for data saving
  CE-sign

Technical Data:

Measuring range	300ng - 500microg/l 
Sensitivity		<0,1 microg/l Atrazin
Weight			40kg
Size (HxWxD)		600x380x350mm
Housing		steel varnished
Protection		IP55
Voltage			230V 
Connection charge	200W
Analogue output	2 x 4-20mA
Intersection 		2 x RS232
Alarm			1 
Sample temperature	0 - 30 C
Sample volume		30ml
Data capacity		1000 
Maintenance interval	> 7 Days

The right to make technical changes is reserved


	If you are interested please contact:

	bbe
	MOLDAENKE


	Schauenburgerstr. 116
	D - 24118 Kiel
	Telefon + (0) 431/5 606 606
	Telefax + (0) 431/5 606 609
	BBE.Moldaenke at t-online.de 







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