1 The world leader in serving science picoSpin 45 & 80 Maintenance, Troubleshooting & LRU’s

1The world leader in serving science

picoSpin 45 & 80

Maintenance, Troubleshooting & LRU’s

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Key Learning

• Cartridge Exchange• Hints & Tips• Troubleshooting• LRU’s

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Capillary Cartridge Exchange

Sub-panel

Flange

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Cartridge Exchange

Cartridge Maintenance is important aspect of maintaining a picoSpin 45 & 80

•Pre-filter sample or use a syringe filter

•Displace samples with clean solvents

•Avoid precipitation reactions (important for dissolved solid sampling)o Displace samples using appropriate solvents

•Leave water, ethanol or acetone in the cartridge for overnight storage

•Clean cartridges with 60-100 µL injections ofo EtOH, acetone, CHCl3 or other compatible solvents

•Replace frit-filter on inlet fitting (outlet fitting does not have a frit-filter)

•In extreme cases where damage has occurred to the cartridge it will have to be replaced

•Following are instructions for replacing the cartridge and re-shimming the magnet

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Cartridge Exchange

Step 1

Turn off and unplug the unit

1.Loosen and remove the (4) knurled screws on the corners of the cartridge sub-panel.

2.Screw the threaded end of the aluminum cartridge removal tool into the cartridge flange as shown in Figure 1.3.Gently pull the sub-panel away from the front panel of the unit a few millimeters and lower it to rest on the U-shaped channel.

Figure 1. Installing the cartridge removal tool

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Cartridge Exchange

Step 2

1.Loosen the (2) two hex head screws, as shown in Figure 3. securing the cartridge flange to the magnet using the long-handled hex wrench supplied with the replacement cartridge. The bushings will retain the bolts so that they cannot fall out and become lost inside the unit.

2.Holding the cartridge removal tool with one hand and the cartridge sub-panel with the other, gently remove the cartridge from the spectrometer as shown in Figure 3.

Figure 2. Loosening the cartridge screws

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Cartridge Exchange

Step 3

1.Reinstall new cartridge by reversing the above steps. Before inserting the cartridge into the spectrometer, check that it is free of dirt and dust. Blow the cartridge off with clean, filtered air if available. 2.After the new cartridge has been installed the unit can be switched on again. Wait for the magnet temperature to stabilize and the follow the instructions for Shimming After a Cartridge Change.

Figure 3. Removing the cartridge from the spectrometer

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Cartridge Exchange Shimming: 1

Cartridge shimming requires additional steps:

Step 1

1.Browse to the autoShim script2.Check/adjust the parameters in Red3.Run the script4.Position your signal within ±500 Hz5.Run the script again

6.When finished continue to Step 2

Parameter Value

tx frequency proton Larmor frequency (MHz)

max iteration 100

test run Checked

linear increments 0.05

quadratic increments 0

target rms 1

pulse width 90° from test report

acq. Points 1000

zero filling 8000

rx recovery delay 500 us

T1 recovery delay 8 s

bandwidth 64 kHz

post-filter atten. 7

phase correction 0 degrees (or any value)

exp. Filter 0 Hz

max plot points 400

max time to plot 12 ms

min freq. to plot -32000 Hz

max freq. to plot +32000 Hz

magnitude Checked

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Step 2

1.Check/adjust the parameters in Red2.Run the script3.Position your signal within to ±500 Hz4.Run the script again5.Uncheck test run and execute script

6.Continue to Step 3

Parameter Value


max iteration 100

test run Checked


quadratic increments 0

target rms 1


acq. Points 1000

zero filling 8000



bandwidth 16 kHz



exp. filter 0 Hz

max plot points 400




magnitude Checked

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Step 3

1.Check/adjust the parameters in Red2.Run the script3.Position your signal within to ±500 Hz4.Run the script again5.Uncheck test run and execute script

6.Continue to Step 4

Parameter Value


max iteration 100

test run Checked


quadratic increments 0.1

target rms 1


acq. Points 200

zero filling 1000



bandwidth 4 kHz



exp. filter 0 Hz

max plot points 400




magnitude checked

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Step 41.Check/adjust the parameters in Red2.Run the script3.Position your signal within to ±500 Hz4.Run the script again5.Uncheck test run and execute script

Your instrument is now shimmed!

Parameter Value


max iteration 100

test run Checked


quadratic increments 0.02

target rms 1


acq. Points 1000

zero filling 8000



bandwidth 4 kHz



exp. Filter 0 Hz

max plot points 400




magnitude checked

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Shimming From Scratch

In rare situations it may be necessary to shim a spectrometer with no prior knowledge of the Larmor frequency and with no starting shim settings. In this case we use the Search script to find the signal.

These steps are required if shimming from scratch:1.Browse to the search script2.Check/adjust the parameters3.Run the script4.Locate signal5.Browse to autoShim script6.Follow Cartridge-change Shimming procedure

Parameter Value

start frequency 46.0 Hz

stop frequency 43.5 Hz

frequency step -8 kHz

SNR 20

noise window start -4000 Hz

noise window stop -1000 Hz

pulse width 40 us or best 90-deg time

acq. Points 200

zero filling 8000



bandwidth 16 kHz



exp. Filter 0 Hz

max plot points 400




magnitude checked

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Hints and Tips

PicoSpin

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Shimming Do’s and Don’tsDO

•Do keep your instrument temperature stabilized 24/7•Do start with the signal between 200-300•Do check the shim daily when in use

• Periodically when not in use•Do perform Maintenance shimming daily when in use•Do include quadratic increments for in maintenance shimming•Do save named shim files weekly•Do include date and magnet temp in name•Do capture a screen shot of shimmed FID/spectrum

DO NOT

•Do not use less than 100 iterations when shimming•Do not shim when the magnet temperature is fluctuating•Do not allow the peak to drift outside the 0-500 Hz range•Do not shim using more than 1000 acquisition points or 400 plot points

Other Tips

•A successful shim will write values to the UI – SAVE THEM•You must execute the autoShim script with test run to write values to shim electronics•An aborted shim WILL NOT write values to the UI unless autoShim has made improvements

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Is the picoSpin Properly Shimmed?There are two methods to determine if your instrument is properly shimmed:

Evaluate the FID and spectrum signal:Look for a slow decay of the FID. The intensity of the FID at 250ms should decrease to no less than about half the initial intensity as shown below.

Compare spectrum peak height value to the test report:Upon completion of the shim script, adjust the Tx frequency to position the peak

about the same offset as show in y our test report. Then compare the shimmed spectrum peak height to the factory spectrum peak height show in your test report.

The spectrum peak height from your shim should be within 5% of the factory spectrum peak height for your instrument or higher .

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Troubleshooting

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Troubleshooting

The most common troubleshooting service calls arise a lack of understanding of the Tx frequency, and misinterpretation of the FID and spectrum plots.

These are the typical reasons underlying a troubleshooting call: Air in in the RF coil Poor shim Misplaced Tx frequency Sample handling Computer connection

On the following pages are examples of typical troubleshooting scenarios for: Good FID, good spectrum Poor FID No FID, good spectrum Good FID, no signal No FID, no spectrum

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Good FID

Good FID

• Both FID and Spectrum suggest a well shimmed instrument

Good Spectrum

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No FID?

No FID?

Good spectrum, but at 0 Hz

• The spectrum appears good but is placed on 0 Hz• Position signal between +200 Hz and + 300 Hz

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Poor FID

• The FID and spectrum are of poor quality• Shim the instrument

Poor FID?

Poor spectrum?

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Good FID, No signal?

No spectrum

Good FID

• The FID looks good, but the signal is missing from the spectrum• Expand the spectrum plot window to the full bandwidth

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No FID?

?

• No FID can mean air is in the coil or the Tx frequency is very far off

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Computer Trouble

• Cannot establish a connection to the Instrument

• Is the instrument physically connected to the network or LAN?

• Is your network adapter properly configured?

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Sample Handling

• High back-pressure

• Blocked filter:o Back flush the filter with a clean solvento Replace the in-line filter assembly

• Complete loss of signal:

• Immediately after injectiono Injected a bubble, re-inject sample

• During acquisition

• Sample/solvent is too volatile for the setpoint temperatureo Lower setpoint temp. and reshimo Use an alternative solvent

• Loss of signal strength over time

• Inject shim solvent and run autoShim script. Compare to historical values

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Least Repairable Units (LRU’s)

The capillary cartridge is the only replaceable part in the field that may need to be replaced because of problems. Note part number differences for the picoSpin 45 and picoSpin 80. The following page contains other consumable part numbers.

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Least Repairable Units (LRU’s)

Documents

1 The world leader in serving science picoSpin 45 & 80 Maintenance, Troubleshooting & LRU’s