HEL Crystal Eyes Manual

Transcription

1 HEL Crystal Eyes Manual

2 Contents 1. Introduction Temperature Probe Temperature Calibration Turbidity Probe Set up of the reflection probe Turbidity calibration Circulator Operation Typical data The recrystallisation of 4-acetylbiphenyl from toluene Running Experiment & Data Monitoring Options under File menu Options under Set Up menu Options in the Window Menu Help Shortcuts Logging Data View Text View Graph

3 1. Introduction Crystal Eyes is designed to measure turbidity change in chemical systems. The system includes the electronics, probes, mini-pc, and software suited for the application ready to run. The ChemLog electronics unit has dedicated channels for monitoring turbidity and temperature. The included software will allow for the data to be saved by clicking on the logging data button. These data files can be analysed in iq or imported into Excel. 2.Temperature Probe It is possible to supply a different length and material of the temperature probe for monitoring/controlling the reactor temperature. When running an experiment make sure the probe is immersed in the reaction medium. Typical temperature range: -40 C to 200 C Temperature Calibration Plug the temperature cable into calibration equipment. Go to Set up/calibration/inputs And click on the Reactor temperature offset. (See page 9 for details) This enables you to open Smart cal window. In the first row type the real value for the first calibration point. Allow the channel to stabilize and hit the average button. When the sample count is 200. Set the second calibration point on the calibration equipment and type this value (real value) in the second row in the smart cal window. When signal stable hit the average button again and wait till sample count is 200. Then press the calculate button followed by the save button 3. Turbidity Probe A standard reflection probe is dipped into the reaction medium and changes in the amount of reflected light are monitored as the experiment progresses. In this way the probe can be used to detect changes in turbidity and its primary application is in detecting the on-set points of crystallization. In simple terms turbidity is a measure of relative sample clarity. 3

4 Light is transmitted via a bundle of six fibres to the probe end where it crosses the gap to the reflector. The back reflected light returns into a seventh read fibre. The amount of reflected light is converted to a voltage signal and recorded by the WinISO software. When the light beam passes through a clear solution the light passes through relatively unobstructed (except for absorption i.e. colour) to the probe reflector and is reflected back into the read fibre of the probe. However in the presence of suspended particulates the light is scattered in all directions and the intensity of the light beam is reduced. This change in intensity and hence voltage signal is detected in the WinISO software. Absorption from dissolved substances can also reduce the intensity of the light beam and hence where possible colour should be taken into consideration during the calibration procedure. Please note that the calibration procedure, described below, can take into account the presence of colour although it will not be able to take into account significant changes in colour. However, any signal output changes due to changes in colour will generally be much less than those signal output changes due to changes in turbidity Set up of the reflection probe The gap length between the probe tip and the reflector should typically be 4 to 5mm Turbidity calibration Before every recrystallisation experiment is run the reflection probe must first be adequately calibrated. Calibration is necessary to ensure a satisfactory baseline and that there is an adequate change in voltage with change in turbidity. Prepare two samples for calibration, one the neat recrystallisation solvent(s) and the other the recrystallisation solvent(s) and solid slurry. Immerse the turbidity probe in the neat solvent(s) ensuring that the gap between probe tip and reflector is completely covered. Allow the signal to stabilize. NOTE: It can be useful to log the calibration for future reference and this is done by selecting the logging data icon in the Main Mimic window. Select the display graph icon also and display the turbidity signal. Using the turbidity calibration dial on the electronics rack adjust the signal ( which is visible on the mimic diagram above the turbidity) to between 0.5 and 1.0 V, allowing a short time for the signal to stabilize. Further adjustments of the dial will not be necessary. 4

5 Next immerse the turbidity probe in the recrystallisation slurry and turn on the agitator to give good mixing. This is a check only, to ensure that the output signal increases from the baseline level set above. 4. Circulator Set point for the circulator temperature is set from the Main Mimic Window. By double clicking on the huber it allows the user to define and customise the set point for the circulator. Set the circulator status ON, type in the required set point for the circulator temperature When the window is modified press OK. 5

6 5. Operation Once the turbidity calibration has been performed the experiment can then be run in the normal way using WinISO. When Logging data the CrystalEyes software will save the time, reactor temperature, turbidity plus any additional hardware. Assemble the temperature and turbidity probe into a suitable reactor vessel and doubleclick on the circulator set point on the mimic screen, set the required set point and set the Circulator Status to ON. Then by clicking on the Logging Button start logging data. By clicking on the Graph shortcut without logging data the software will ask you if you would like to start logging data. Note that without logging data the software is unable to plot any graph. When experiment is finished set the Circulator Status to Off stop logging data by clicking on the logging shortcut on the mimic screen. Data will be automatically saved. This data can then be open in iq software and analysed. Note that the probe will respond to any variable that will cause a change in the intensity of the light beam. Thus, not only will the probe respond to changes in sample turbidity it will also respond to other physical effects such as bubbles in solution (this can be evident in aqueous systems) or absorption effects due to colour changes. 6. Typical data 6.1 The recrystallisation of 4-acetylbiphenyl from toluene The following describes a typical recrystallisation experiment in detail: 1) Into a suitable 50ml cell add 4-acetylbiphenyl (6.0g). 2) Into the reactor cell also add toluene (30ml) and then cover with parafilm to prevent evaporation. 3) In a clean beaker have some neat toluene available for use in calibration. 4) Immerse the turbidity probe in the neat toluene ensuring that the gap between probe tip and reflector is completely covered. Allow the signal to stabilize. Using the turbidity calibration dial on the electronics rack adjust the signal to between 0.5 and 1.0 V, allowing a short time for the signal to stabilize. Further adjustments of the dial will not be necessary. 5) Immerse the turbidity probe in the recrystallisation slurry prepared above; agitation is required to give good mixing. Observe that the turbidity signal increases. This is a check only, to ensure that the output signal increases from the baseline level set above. 6

7 6) Run an experiment with the following steps: Hold the reactor constant at 25 o C for 5 minutes Heat reactor slowly to 60 o C (1 or 2 o C/min) Hold reactor constant at 60 o C for 5 minutes Cool down reactor slowly to 25 o C ( -1 o C/min or slower) 7) Plot the resulting temperature and turbidity data. It should look similar to the graphs below: 7

8 7. Running Experiment & Data Monitoring WinISO can be started fromby either doubleclicing on the WinISO shortcut icon set up in the Windows desktop or by use of a mouse to click on the WinISO directory in the programs sub-directory under start Everything that is required to start running experiment or logging data can be accessed from the main mimic screen in addition to performing the temperature and turbidity probe calibration. Main menu bar Circulator Temperature & set point Turbidity Reactor Temperature Shortcuts 8

9 The Main Menu bar offers the main level of commands. As with most Windows applications it uses pull down menus. File Enables the user to create a new Main Mimic Window, run WinISO in simulation or real-time mode, display the Event log and Exit the WinISO program. Setup Window Help Enables the user to Calibrate devices. Enables the user to Arrange, tile, cascade and close all windows within the Main mimic Window. Enables access of the WinISO online Help. The About option displays details of the WinISO version installed. 7.1 Options under File menu Simulate The simulation mode is a training mode of the software identical to the real time version but does not require the hardware to be present. Event log This keeps a record of the system operations and will provides essential contact information such as the start or end of logging or any error messages that devices might return during operation. Exit This exits the program 7.2 Options under Set Up menu This section describes the Set-Up option of the main menu. When this option is selected a sub-menu will appear as shown below On selecting the Inputs option of the Calibrations menu the Analogue Channel Calibration window is generated 9

10 The Analogue Channel Calibration window lists all the analogue input channels available in the system and shows their current calibration parameters (offset and gain) together with the raw (normally 0-10 Volts) and the real values. The real value is the data, which is displayed in the Live Data window and in the mimic window. It is derived from the raw valve after the calibration has been performed. If the offset and gain for a particular channel are known they can be entered manually via the keyboard. Alternatively, the values for the selected channel can be determined semi-automatically using the Smart Calibration facility. This can be selected by pressing the Smart Cal. button. The Smart Calibration window will then be generated. Add/Delete buttons Calculate Button Sample count Average Button Close window The Smart Calibration window allows the user to calculate the gain and offset of a device by measuring the averaged raw values at two or more known real values. The add and delete buttons allow the number of values for the calculation to be changed. The average button starts the averaging of the raw value over 200 cycles, which takes around 20secs. The progress of the averaging is shown in the sample count box. The user must enter the real value in the appropriate cell in the window. When the 10

11 averaging has been completed for the required number of values the calculate button starts the calculation of gain and offset for the channel. The values displayed in the Analogue Channel Calibration window will be updated automatically. When the calibration of the analogue inputs is complete the values can be stored by pressing the save button. If the user does not do this they will be prompted to whether the new values are to be saved on exiting the window. Devices/controls If the Devices/controls option is selected from the Calibrations sub-menu the Gencalibform window will appear as shown. In this window all of the loops or devices available in the system are listed On selecting the Save button at the bottom of the window changes to calibration values are stored. The Cancel button discards any changes that have been made. Both buttons will then close the Window Options in the Window Menu This option of the main menu provides general windows functions, by choosing one of the options available the user can manipulate the presentation of the windows on the screen to their preferred arrangement 7.4. Help This opens the on-line help program (not present with all systems) 11

12 8. Shortcuts WinISO makes extensive use of shortcuts to enable the user quick and easy access to the window screens necessary for the simultaneous monitoring and control of reactor systems. Mimic form Graph Window Start/Stop Logging data Exit Program Text data 8.1 Logging Data The logging data button allows the user to initiate data logging. When choosing this option the user is prompted to select a name and a directory for the output data file. 12

13 8.2 View Text This button toggles on and off the Live Data Text window as shown below 8.3 View Graph This button allows the user to view experimental data graphically as a plan is run. Data Legends Edit Graph By clicking on the Edit Graph button it allows the user to edit and customise the data displayed. 13

14 Parameter column Axes indicator Axes editing window Define markers Axes selection box Line colour selection palette Line Width editing Toolbar Marker style editing Toolbar Line style Toolbar 14

15 Clicing on the Axis button the Axes Configuration window is called up. Using this window the user can define the maximum and minimum values of the three axes and the number of interval values to be displayed. Axes Scale box Display grid box Decimal places box Rescale options box Full screen/ narrow screen selector box 15