Features
The QUANTULUS™ MCA is user-controlled by logic commands
that allow hundreds of tailored counting configurations in addition
to default ones. For convenience, you can access samples in any
order with the random access sample change. The system includes PC
software to allow complete data processing and the plotting of up
to six spectra on screen. Its capacity to handle microvolumes means
that it provides an easy, competitive liquid scintillation counting
solution for 14C-dating problems solvable by expensive Accelerator
Mass Spectrometry.
- Selected Phototubes:
QUANTULUS phototubes are
selected for low inherent background and spectral stability and
meet with the strict specification of high quantum efficiency.
- Passive Attenuation of External Radiation:
The
asymmetric passive radiation shield attenuates most of the
environmental gamma Radiation.
- True Background Reduction by Coincidence Event
Detection:
Able to remove much of the sample signal from
low energy environmental gamma radiation and almost 100% of the GeV
muon particles, whose flux varies due to changes in atmospheric
pressure and humidity. There is no need for atmospheric pressure
correction in QUANTULUS during long counting periods.
- Guard - Optical isolation assures no
misclassifications:
The true excellence of Wallac's
coincidence event detection stems from optical isolation of the
sample detector and the guard detector. The sample quality and
fluors do not affect the background reduction performance. Sample
light does not penetrate into the guard detector. This unique
method performs background reduction without efficiency losses,
i.e. without errors in interpretation of the origin of sample
events.
- Logarithmic MCA's for resolution where you really need
it:
Two dual multi-channel analyzers in QUANTULUS ensure
storage of full spectral: information - even rejected counts can be
saved when necessary. Five spectra for each sample can be saved in
both instruments.
- Pulse Shape Analysis:
Pulse Shape Analyzer
(PSA), standard feature in QUANTULUS, allows simultaneous
acquisition of pure alpha and beta spectra from mixed radiations of
a sample. Pioneered by Wallac, PSA is a necessary condition for
sensitive liquid scintillation alpha counting.
- Pulse Amplitude Comparison (PAC):
PAC is used
to reject crosstalk between phototubes. This type of background,
where pulses are in great disparity, is created in phototubes by
their inherent radioactivity and by external radiation. Improved
figure of merit is achieved since true sample events have very much
less variation in amplitude ratio and are not rejected by the
comparator.
- Bias Threshold:
High bias threshold is
available for elimination of low energy glass vial background below
Ch 300 and improving background and figure of merit for high energy
beta emitters, as for 14C.
- Rejection of EM Interference:
To ultimate
stability requires rejection of any electromagnetic interferences
that could creep into the sample spectra. This is carried out with
an aerial, which temporarily inhibits sample counting in the
presence of such interferences.
- Rejection of Static Electricity:
Static
electricity is removed by metallic cylinders that act as sample
holders in cassettes and light shutters, when the sample is raised
into the counting chamber - in this process high voltage discharge
deionizes the residual static charge from vials.
- ACSS for Immediate Self Stabilization:
Automatic Continuous Spectrum Stabilization (ACSS) ensures gain
stability with no loss of counting time, and with no warm-up time,
for example after power failure. A double feedback system checks
100 times per minute and, if necessary adjusts PMT response.
- Low Activity External Standard for Fast Quench
Correction:
High energy, low activity gamma source (152Eu,
37 kBq) ensures good quench index also for low energies and high
quench levels. Logarithmic spectrum end point is well defined and
therefore used in QUANTULUS as an index of quench, SQP(E) or
External Standard Quench Parameter. The advantages of the Compton
electron spectrum based quench index are fast, non-destructive, and
easy evaluation of quench, even with low activity and background
samples.
- Random Access Sample Change:
Highly flexible
sample handling is achieved by means of the three
software-controlled 4 x 5 matrix sample trays, allowing totally
random access to any sample, which, when used in conjunction with
the possibility of individually programming up to 60 sequential
samples in any order. This allows the user to choose the
combination of counting time, sequence and repeat measurements best
suited to a particular application.
- Cooling - Noiseless Peltier Units:
For
operation under extreme or variable conditions, the sample chamber
and interior of the instrument are maintained at a constant
temperature within 12°C of ambient. The cooling of four
electronic noisefree Peltier elements can be boosted using water
circulation.
Specifications
Software
User Interface, Protocol Editor and Data Acquisition Software
Windows user interface 1224-307 WinQ, spectrum analysis program and 1224-534 EASY View are included in the 1220-003 QUANTULUS™ configuration. Software runs in Windows 95, 98 and NT.
WinQ is easy to use with features such as drop down menus and context sensitive help messages. It allows you to control one or four QUANTULUS™ instruments and gives you live display of spectra on screen. You can use it to queue up an unlimited number of jobs, and it keeps a log of all the jobs that have been run. WinQ allows you automatic or manual storage path naming and you can copy protocols to other users. The program can be operated and data can be stored through LAN. Access via Internet is possible with additional networking software. There are default MCA settings for 3H (or any other low energy beta emitter), 14C (or any other high-energy emitter) and for alpha/beta spectrum separation. An unlimited number of parameter groups can be stored permanently on hard disk. During protocol editing, comment texts can be added to the final results printout file. Also, if you need to, can easily access the QUANTULUS™ internal line editor.
If, while QUANTULUS™ is counting, you wish to leave the program, you can do so. When you return to WinQ there is automatic recovery of data transmission. While Spectrum Analysis software is being used, WinQ operates as resident.
Spectrum Analysis Software
1224-534 EASY View is a Windows 95, 98 NT 4.0 spectrum analysis software for QUANTULUS™ raw spectrum display and processing works also for old instruments.
- The program works in the selected high resolution color graphics mode and can be used simultaneously with data acquisition
- Displays up to 6 spectra simultaneously
- Also rejected count spectra can be displayed
- Manual scaling or auto scaling
- Spectrum noise filtering weighted least squares fit
- Zoom energy range
- 14C age calculation routine
- Eff, figure of merit, sample activity in Bq and pCi, 3H activity in Bq, pCi and TU
- Detection limits Bq/l and pCi/l
- Single label DPM
- Dual label DPM counting with quench correction (SQP(E)) by Three over Two method
- All calculation in user definable (soft) Windows
- User definable calculations in an Excel type spreadsheet (Formula 1)
- Save of spreadsheet in Excel formats
- Automatic summing of cycled and/or repeated spectra
- Spectrum subtraction
- Time series counting statistics
- Chi-squared and level of significance, Levy-Jennings plot
- Outlier identification and exclusion
- Spectra stored in ASCII format
- Color hardcopy on Windows printers
- Windows help
- Year 2000 compliant
Options & Accessories
| Instrument | |
| 1220-003 | Floor standing, Low level LSC, 20 mL vials, 60 samples, detector and guard detector included |
| 1220-307 | WinQ, user interface, protocol editor and data acquisition software |
| 1224-534 | EASY View Spectrum Analysis Program |
| 1220-102 | Pulse Shape Analyzer |
Optional Items
| Instrument | |
| 1220-103 | Cooling Unit |
| 1220-500 | Copper-PTFE vials, volume 3 mL, pkg of 10 |
| 1220-501 | Copper-PTFE vials, volume 7 mL, pkg of 10 |
| 1220-502 | Copper-PTFE vials, volume 15 mL, pkg of 10 |
| 1220-503 | Copper-PTFE vials, volume 20 mL, pkg of 10 |
| 1200-422 | Super low diffusion polyvials 20 mL, PTFE coated polyethene, pkg of 100 (caps included) |
| 1200-420 | Plastic vials 20 mL with caps, pkg of 1,000 |
| 1210-131 | Glass vials 20 mL, low K-40 content, pkg of 500 |
| 1200-437 | Optiphase HiSafe 3, water miscible cocktail 5 L |
| 1200-436 | Optiphase HiSafe 2, water miscible cocktail 5 L |
| 1200-440 | Optiphase TriSafe, water miscible cocktail 5 L |
| 1205-440 | Betaplate Scint, for organic samples 5 L |
| 1210-120 | 3 H for organic solvents, 40 capsules |
| 1210-121 | Internal std kit, 3H for aqueous solvents, 40 capsules |
| 1210-122 | Internal std kit, 14C for organic solvents, 40 capsules |
| 1210-123 | Internal std kit, 14C for aqueous solvents, 40 capsules |
| 1210-124 | Internal std kit, combination pkg; 3H -O; 3H -W; 14C -O; 14C -W, 10 capsules each |
Optional Software for MSDOS Environment
| Instrument | |
| 1220-305 | Queue Manager, v. 1.2, user interface, protocol editor and data acquisition software, y2k compatible |
| 1220-302 | Spectrum Analysis Software, v. 3.2, y2k compatible |