SF.3 Stopped-Flow Accessory - Specifications
Specifications
Description
The SF.3 is purpose designed for high performance stopped-flow research. The standard system provides single mixing, circular dichroism and absorbance detection, scanning capability in steady-state and kinetic modes, all of outstanding sensitivity. It features a biocompatible and fully thermostatted flow circuit and supports large ratio asymmetric mixing. Data acquisition, display and analysis is provided by our Pro-Data software running under Windows™ XP, and is fully integrated into the Chirascan's software suite providing unrivalled ease-of-use. Pro-Data provides an integrated and easy to use environment with flexible and powerful functionality for a wide range of stopped-flow kinetics and equilibrium applications.
General information
- Measurement modes: Circular dichroism, Absorbance, Fluorescence, Fluorescence Polarisation/Anisotropy, Sequential Mixing, Quench-Flow. Optimised for both circular dichroism / absorbance and fluorescence detection without the need for reconfiguration.
- Option for standard Chirascan 150W air cooled xenon (ozone-producing) or 150W Hg-Xe lamp.
- Stopped-flow sample handling unit fitted with removable cell cartridges. The standard 20µL volume cell has a dead-time of 1.1ms, optical pathlengths of 10mm and 2mm, and is suitable for circular dichroism, absorbance and fluorescence work. A shorter dead-time 5µL cell can also be fitted.
- Flow circuit materials are suitable for anaerobic experiments and resistant to aggressive reagents.
- Very wide temperature range (-20°C to +60°C).
- Minimum sample volume requirement of 40µL per syringe.
- Pro-Data Windows® XP™ control software with comprehensive acquisition, display and analysis tools. Standard features include: wavelength scanning, repeat drives for signal averaging, acquisition of time-resolved spectra (Spectra-Kinetic technique), linear, logarithmic and split timebase and digital oversampling capability.
Sample Handling Unit
| Number of view ports | Two transmission/emission; One dedicated emission | ||
| Cell volume (standard cell) | 20µL | ||
| Optical path (transmission) | 2mm and 10mm | ||
| Cell volume (optional cell) | 5µL | ||
| Optical path (transmission) | 1mm and 5mm | ||
| Dead time (standard cell) | 1.1ms (1:1 mix) 1.6ms (10:1 mix) | ||
| Maximum final reagent flow rate | 18.5mL/ms (1:1 mix) | ||
| Typical reagent volume per shot | 50µL of each reagent (1:1 mix) | ||
| Drive ratios using appropriate syringes | 1:1; 2.5:1; 5:1; 10:1; 25:1 | ||
| Drive mechanism | Pneumatic drive for fast response with automatic sample empty (multiple shots) | ||
| Sequential mixing operations | |||
| Age time range | 15ms to > 1000s (continuously variable) | ||
| Age time selection | Directly from control software (no hardware reconfiguration required) | ||
| Calculated dead time | Recorded with each drive | ||
| Calculated age time | Recorded with each drive | ||
| Drive profiles | Recorded with each drive | ||
| Drive volumes | Recorded with each drive | ||
The drive syringes, flow lines and optical cell are surrounded by a thermostat bath. The flow circuit is chemically inert and free of stainless steel and rubber. It is constructed of glass (syringe barrels), silica (optical detection cell), PEEK (sample flow circuit tubing and drive valves) and Teflon (syringe piston seals). A supply of compressed gas, usually nitrogen or air (8 bar pressure), is required to operate the rams.
Electronics & Software
| Data acquisition resolution | 16 bit | ||
| Data input range | +10V to –10V | ||
| Maximum digitization range | 100kHz | ||
| Acquisition period – timebase 1 | From 5ms to 360000s | ||
| Acquisition period – timebase 2 | From 1.25ms to 10000s | ||
| Logarithmic acquisition period | From 1ms to 10000s | ||
| Data oversampling | 100kHz data sampling on linear timebases, variable on log timebase | ||
| Auto-range | Automatic optimisation of range settings |
The Electronics Unit provides automated control of the sample handling unit and monochromator wavelength setting plus signal acquisition from the photomultiplier tube detectors and data processing. The modular design of the Chirascan electronics means only required features need be installed and in the unlikely event of a fault, these are localised, readily identified and if necessary can be quickly and easily repaired by substitution of the appropriate module.
Chirascan - The Worlds Most Advanced Circular Dichroism Spectrometer
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