The Mercury Tracker 3000 serves for measurement
of the mercury concentration in air and other gases. It has multiple
applications including:
mercury surveys
mercury spills screening work place monitoring to avoid
mercury exposure ground air screening investigation of
contaminated sites hazardous waste inspection.
Measuring
principle
The mercury concentration is
measured in an optical cell entirely made of a high purity grade
fused silica. A maintenance-free membrane pump continuously feeds
the sample gas to the optical cell where light absorption
measurement takes place at a wavelength of 253.7 nm. This so-called
"cold vapor" measuring method is extremely sensitive for mercury
determination and has been used successfully for many years.
Analytical
Performance
The Mercury Tracker 3000 uses a
high-frequency driven electrodeless Hg low pressure (EDL) lamp as UV
source. It generates emission lines of an extremely narrow bandwidth
which are congruent with the absorption lines of the Hg atoms.
Cross-sensitivities are thus minimized. Unlike the gold film based
systems measurements are not interfered by H2S. The extremely high
stability of the UV source is a result of the reference beam method
which is applied in the Mercury Tracker 3000. Total background noise
is less than 0.1 µg/m3. To prevent temperature drift both the lamp
unit and the detectors are temperature-stabilized. The instrument is
calibrated before delivery and keeps the calibration for a long
period of time. For quality control a test screen is included in the
delivery allowing the user to check calibration.
Special Features
Rugged aluminum
case. Comfortable shoulder strap. Wand with grip and sample
tubing. Operates up to six hours on fully charged
batteries. Membrane pump with long service life. Sample input
filter with Teflon membrane. Unsurpassed stable optical bench.
Factory-calibration with long-term stability
Easy to operate
The user controls the Mercury
Tracker 3000 by menu-guided inputs via a waterproof membrane keypad.
After switch-on the light source is stabilized (approx. 1 - 5
minutes). Measurement starts automatically, continuously indicating
the measured mercury concentration of the sample air as a numerical
value and a graphic bar. The zero point is automatically adjusted by
the auto zero function. Following settings can be entered in the
parameters menu: duration and repeat interval of the zero
adjustment, selection of the concentration unit (µg/m3 or ppb),
measuring range (0-100, 0-1000, 0-2000 µg/m3), input of three
different alarm levels, calculation of a mean value over three
freely selectable time intervals, printer activation.
Display and Output of
Measurements
The result of the measurement is
displayed on an LCD in real time, both numerically and graphically
and is output as an electrical signal of 4-20 mA. The Mercury
Tracker 3000 has outputs for alarm, status and measurement values
for recording or full integration in plant control systems. The
device also has a serial interface (RS 232) for data transfer to a
PC.
Self Diagnosis
System
If an important component of the
Mercury Tracker 3000 malfunctions the user is warned via the display
(blinking messages: clean cell, lamp, low battery, alarm) and via
output signals.
Mobile Use
The Mercury Tracker 3000 has a
built-in rechargable battery with a capacity for six hours
operation. For longer employments the battery pack can quickly be
exchanged for fully charged spare batteries. A microprocessor
controlled charger unit comes with the instrument. With an
optionally available cigarette lighter adapter cable the instrument
can be operated by the car battery. The instrument can be carried
with an ergonomically shaped shoulder strap. The wand connected to
the sample inlet allows to check spots or to screen areas for
mercury concentrations. The comparatively low sample flow rate
minimizes influences of the instrument itself on the mercury
concentration over hot spots.
Data Logger
Function
The Mercury Tracker 3000 features a
built-in data logger. Up to 30000 readings can be stored in the data
memory. The logging interval can be set from 1 to 16 seconds giving
a total recording capacity of 4-60 hours. The stored data can be
read out with a PC using the serial interface of the Mercury Tracker
3000 according RS232 standard.
Mercury Tracker 3000
Technical Specifications
Measuring
principle:
UV-Absorption
Wavelength:
253,7
nm
UV
source:
Electrodeless
low-pressure mercury lamp
Stabilization
method:
reference beam and
thermal
Optical
cell:
Fused silica
(Suprasil), ca. 230 mm length
Measuring
range:
0...100
µg/m³ 0...1000 µg/m³ 0...2000 µg/m³
Sensitivity:
0.1
µg/m³
Response time (99%
signal):
1
second
Computation of
mean value:
Automatically via
three freely selectable time intervals
Alarm:
status contacts
and optical, when concentration is exceeded, 3 levels are
programmable
