THERMO SCIENTIFIC NICOLET IS10 (02) PDF Document

The manual for the THERMO SCIENTIFIC NICOLET IS10 uses the following conventions for providing safety and other special information:

WARNING: Indicates a hazardous situation which, if not avoided, could result in death or serious injury.

CAUTION: Indicates a hazardous situation which, if not avoided, could result in minor or moderate injury.

NOTICE: Follow instructions with this label to avoid damaging the system hardware or losing data.

Note: Contains helpful supplementary information.

Tip: Provides helpful information that can make a task easier.

The following features are visible from the front and sides of the THERMO SCIENTIFIC NICOLET IS10 AEM module:

Sample compartment: Place your accessories and samples here for analysis. A focused IR beam is reflected from the spectrometer to the sample in this compartment. The beam is focused at the center of the sample compartment, at a height of approximately 9 cm (3.5 in) when measured from an installed standard transmission baseplate.

Detector compartment: Up to three detectors can be installed at the same time: two interchangeable and one fixed DTGS.

Detector fill port: Used to add liquid nitrogen to the dewar to cool an MCT detector before each use.

External beam port (left side): Light from the spectrometer passes through this port to the AEM module’s sample compartment input optics.

Desiccant compartment: Contains desiccant to prevent moisture from damaging the optics. If the system is not purged, the desiccant must be installed and monitored.

Touch Point: Automatically configures the spectrometer for sampling with the AEM module. The LED on the Touch Point shows the status of the AEM module.

The Touch Point LED on the THERMO SCIENTIFIC NICOLET IS10 AEM module has three states that indicate its status:

There are two connectors inside the sample compartment of the THERMO SCIENTIFIC NICOLET IS10 AEM module:

Purge Out Connector: This can be fitted with a purge exhaust to disperse purge gas into the AEM module’s sample compartment.

Accessory Connector: If you have a photoacoustic or other accessory that has a detector or motor, connect the cable from the accessory to this standard 25-pin connector. Note that this is not a pass-through connector. If the accessory has a 15-pin connector, use the sample compartment accessory adaptor cable that came with your spectrometer to connect it.

The Accessory connector can be used to access power and ground for your own detectors and custom hardware. Only qualified persons should connect custom hardware.

CAUTION: Avoid personal injury. Improper or unsafe cabling can cause damage to your accessory and may create a safety hazard. Do not use this connector for signals that exceed a ±12 VDS. Limit the current to a maximum of 500 mA.

When operating the THERMO SCIENTIFIC NICOLET IS10 AEM module, please observe the following precautions:

Use only dried air or nitrogen to purge the AEM module. The purge gas must be free of oil and other reactive materials. Heat from the source or from laser absorption may ignite flammable gases or reactive materials in purge gas.

Some detectors must be cooled with liquid nitrogen before use. Follow your organization’s Personal Protective Equipment (PPE) and handling guidelines when working with liquid nitrogen.

WARNING: Avoid explosion hazard. Never use a flammable, combustible, or toxic gas to purge this instrument. The purge gas must be free of oil and other reactive materials.

NOTICE: Do not use argon as a purge gas. Argon is an insulator and prevents the system from cooling properly. When chlorinated or fluorinated solvents are present, purge is required as failure to do so could cause accelerated corrosion of optical components.

To connect a purge source, use a splitter or gas manifold to add a second supply line from your purge source. Attach this second line to the purge input connector on the back of the AEM module. The Purge Out connector on the rear wall of the sample compartment is used for purging the sample compartment and special accessories.

Adjust the purge gas pressure and flow rate as described below:

It is recommended that you leave the purge on at all times to keep the AEM module free of undesirable gases, protect the optics, and improve the system’s thermal stability.

If you plan to use an accessory that is purged through the sample compartment windows, such as a gas cell, you must first remove the windows and install sidewall adapters before installing the accessory. The adapters provide a flat surface for the purge tube to tighten against.

Sidewall adapters are also used to secure the optical filter holder. They are included with many optical filter kits and can also be purchased separately.

The THERMO SCIENTIFIC NICOLET IS10 AEM module can have up to three detectors installed. The front detector position holds a room-temperature detector only, while the back position holds either a room-temperature or a cryo-cooled detector. The fixed DTGS detector is not user-replaceable.

WARNING: Avoid shock hazards. Before changing an installed detector, turn off the spectrometer power and disconnect the power cord. Disconnect any accessory cables from the AEM module sample compartment connectors and close the sample compartment cover tightly.

Changing the detector in the front or back position is done using the Snap-In detector design. For specific instructions, refer to “Changing a Detector” in Spectrometer Help Topics. If you are installing a detector that was purchased separately, use the instructions that came with the new detector.

After changing a detector, you must turn on the spectrometer power and select the new detector by choosing Collect > Experiment Setup in the OMNIC software and setting the Detector option, or by opening the Touch Point Setup dialog box for the AEM module and setting the Region option.

An MCT detector must be cooled with liquid nitrogen before you collect data. The dewar is located in the back detector position under the dewar cover.

Equipment needed:

• a small plastic laboratory funnel

• a one-liter, glass-lined or stainless-steel lined laboratory vacuum bottle

• a supply of liquid nitrogen

WARNING: Avoid freeze burns. Liquid nitrogen is extremely cold and potentially hazardous. Wear protective equipment and follow standard laboratory safety practices. Ensure any container used can hold liquid nitrogen safely without breaking. Avoid skin contact with liquid nitrogen.

NOTICE: Do not spill liquid nitrogen onto or near the detector window. Rapid cooling can cause the dewar to lose vacuum. Always fill the dewar with the instrument cover in place.

To cool the detector:

1. Open the detector dewar cover and remove the plastic stopper.

2. Insert a funnel into the liquid nitrogen fill port of the detector dewar.

3. Slowly fill the detector dewar with liquid nitrogen through the funnel. First, cool the funnel and stem by filling the funnel and letting it drain completely into the detector two or three times. Always let the liquid nitrogen flow into the detector before adding more. Cooling the detector too quickly may cause the dewar to rapidly boil off liquid nitrogen. A small amount of spillage will not harm the instrument, but do not overfill.

4. When the detector is nearly full, a small amount of liquid nitrogen will boil off. Let the vapor plume dissipate, replace the plastic stopper, and close the dewar cover.

Allow at least 20 minutes for the detector to cool before use.

You should periodically check the performance of the AEM module using the advanced diagnostics performance test. Keep a log of each test date, result, number of scans, and resolution setting.

To run the performance test:

1. Open OMNIC software.

2. Choose Collect > Advanced Diagnostics.

3. Choose Performance Test.

4. Select the type of beamsplitter installed in the spectrometer.

5. Select an available AEM module detector.

6. Make sure the check boxes for all other tests are cleared.

7. Choose Run Selected Test. The software will collect background and sample scans to generate a 100% transmission spectrum and calculate the signal-to-noise ratio. The result will appear in the Actual column, and a Pass or Fail result will appear in the Status column. A “Pass” result means the actual noise value is less than the expected (maximum allowable) value.

8. Close the Bench Diagnostics window.

If the AEM module fails the performance test, consult the troubleshooting information.

Follow these steps to prepare the AEM module to collect spectra:

1. Power on the spectrometer.

2. Install a sample holder or other sampling accessory in the AEM module sample compartment.

3. Remove any sample from the sample holder or accessory and ensure nothing else is blocking the beam in the AEM module sample compartment.

4. If you are using a liquid nitrogen cooled (MCT) detector, add the liquid nitrogen to the detector dewar.

5. Open OMNIC software.

6. Press the Touch Point on the AEM module to configure the instrument optics for AEM module sampling and load the associated workflow.

7. Choose the Touch Point Setup button in the software and adjust the settings as needed.

8. Wait for the system to stabilize for at least an hour (if the spectrometer had been powered off for more than 20 minutes).

The AEM module Touch Point has a user-configurable workflow that defines everything from background collection to analysis. Once configured, you simply press the Touch Point to start the workflow.

To configure your AEM module workflow:

1. Start OMNIC software.

2. Choose the AEM Touch Point button in the software to configure the instrument.

3. Choose the Touch Point Setup button in the software to open the setup dialog box.

4. In the dialog box, the Sample Compartment will be set to the AEM module. Select an appropriate experiment from the “Experiments Using: AEM” pane.

5. Set the Touch Point Setup options as desired (e.g., resolution, measurement time, background handling, etc.).

6. If you want to overwrite the default settings without overwriting the default experiment file, choose Set Default.

7. Choose Save.

8. If you need to specify other settings, choose Experiment Setup, set the options, choose Save, and then choose OK to close the dialog. Note that some settings appear in both Experiment Setup and Touch Point Setup, and changing them in one location automatically changes them in the other.

The Touch Point dialog box provides commonly used settings that define how your data will be collected, displayed, measured, and reported.

To collect a spectrum for a typical mid-IR experiment, follow these steps:

1. Follow the steps in “Setting Up the AEM.”

2. If your AEM module workflow is not configured, follow the steps to configure it.

3. Press the AEM module Touch Point to start the workflow. If no background spectrum is available, you may be prompted to prepare for background collection.

4. Make sure the sample holder or accessory in the AEM module sample compartment is empty.

5. Choose OK to start collecting a background spectrum. When complete, another message will ask you to prepare to collect the sample data.

6. Place the sample in the sample holder or accessory and close the sample compartment door. If your spectrometer is purged, wait 1 minute for equilibrium to re-establish.

7. Press the Touch Point (or choose OK) to begin collecting the sample data. The Collect window will show the progress. When finished, you may be asked if you want to add the spectrum to a spectral window.

8. Press the Touch Point (or choose OK). The final spectrum appears in the selected spectral window.

If your AEM module is sealed and desiccated (not purged), you must regularly check and occasionally change the desiccant packets to protect the optical components from water vapor.

The desiccant compartment is located towards the back of the AEM module on the left side. Check the round blue indicator on the desiccant compartment cap once a month. Change the desiccant if the indicator is pink or white.

NOTICE: When the spectrometer power is off, keep all covers closed tightly and check the humidity indicator at least once a month. The desiccant should be replaced at least once each year regardless of the color of the humidity indicator. Depending on your lab environment, you may need to replace the desiccant more often.

The AEM module has a potassium bromide (KBr) window on each side of the sample compartment to seal it from moisture. These windows must be clear, clean, and free of fingerprints. If they become scratched, broken, or fogged, they may need to be replaced.

The windows may need to be temporarily removed for certain experiments. When removed, they should be replaced with the open ring assemblies that came with the AEM module to maintain a proper seal.

NOTICE:

• Replace windows only with replacement parts supplied by us.

• Wear non-powdered latex-free gloves or finger cots to handle replacement windows and hold them only by the edges. Fingerprints will permanently damage the windows.

• Do not attempt to clean the windows. To remove dust, blow it off with a gentle stream of pure nitrogen. Do not use compressed air.

• Do not push on the window, rubber gasket, or bracket in any way that bends or distorts it; the window can crack or break. Damage during installation is not covered by the warranty.

• Do not allow liquids to contact the sample compartment windows.

• If your instrument is purged, you can leave the purge on while you replace the windows to prevent ambient air from entering the AEM module.

If one of the following occurs, there may be a loss of communication:

• The AEM module Touch Point button does not appear in the OMNIC software toolbar.

• The AEM module Touch Point does not light when pressed.

• When you choose Collect > Experiment Setup > Bench tab, the AEM module option does not appear in the Sample Compartment drop-down list.

To resolve this, check that the communications cable is installed on the AEM module back panel and that the connector is secured at both ends. If the cable is installed correctly, contact a service representative.

If the spectroscopic signal in the AEM module shows a sudden loss in intensity, the sample compartment windows may be damaged or fogged. Open the sample compartment and inspect the condition of the windows (a small flashlight is recommended).

The windows should be clear, clean, and free of fingerprints. If they are scratched, broken, or fogged, replace them. If the signal is still not satisfactory after replacement, contact a service representative.

Note: If you cannot determine the condition of the windows by inspecting them, remove the windows. If the signal intensity improves significantly, replace the windows.

If the IR beam does not appear in the AEM module sample compartment after you press the AEM module Touch Point, follow these steps to troubleshoot:

1. Press the Touch Point next to the main spectrometer sample compartment and check whether the beam appears there.

2. If the beam appears in the spectrometer sample compartment, there is a problem with the passport mirror that sends the beam to the AEM module.

If the beam does not appear in either sample compartment, contact a service representative.