POWER ON INSTRUCTIONS FOR JASCO 715:

 

1) N2 PURGE--It is important to remove the O2 from the optics compartments so that when the lamp turns on there is no O2 around to react with the UV and deposit on the mirrors! Please check the level of N2 in the tank before your experiment. (When the N2 tank gets to ~1/3 full please contact the Agard lab at  6-9375 or 6-5143 so a replacement tank can be arranged)

         •TURN ON N2 TANK TO ~20 PSI (275L tank against the north wall in S-1076).

         •TURN ON THE SMALL SILVER FLOW ADAPTER BOX AND ADJUST THE N2 FLOW RATE TO 10-15L/MIN (box is on the wall behind the CD machine)

         •PRESS THE RED BUTTON ON THE BOX IN ORDER TO ILLUMINATE THE "LINE" LIGHT ON THE POWER SUPPLY BOX.

 

2) CHECK BEHIND THE SMALL DOOR OF THE CD MACHINE TO BE SURE THAT THE BALANCE METER MODE IS SET TO READ VOLTAGE (PMV) AND THE HT SWITCH IS SET ON AUTO (if is isn't on auto you can easily ruin the PM tube!)

 

3) TURN ON LAMP--POWER 1 ON JASCO POWER SUPPLY (you should hear a little click and then the fan should come on--all in about 5-10 seconds).

 

4) TURN ON CD PHOTOMULTIPLIER--POWER 2 ON JASCO POWER SUPPLY.

 

5) TURN ON COMPUTER MONITOR

 

6) OPEN SPECTRUM MANAGER (STARTà PROGRAMSà JASCO à SPECTRUM MANAGER) AND INITIALIZE HARDWARE BY SELECTING A MEASUREMENT METHOD. This takes several seconds and is necessary prior to any data collection. After the lamp is 300-400 hrs old the HT will often be overange, but this will only affect measurements at very low wavelengths so you may click on ignore if this happens.

 

7) TURN ON TEMPERATURE CONTROL? If you would like to use temperature control in your experiments, TURN ON THE WATER BATH (on the floor), TURN ON THE PELTIER AND PRESS START. OPEN STANDARD MEASUREMENTàHARDWARE MANAGERàTEMPERATURE AND SELECT J343-TC. (set desired temperature under current settings).

8) LAMP EQUILIBRATION TIME = 30 MINUTES. You should wait this time for optimal stability in the lamp output once the lamp is on.

 

9) SIGN IN TO THE LOGBOOK. PRIOR TO DATA COLLECTION YOU MUST LOG IN AND RECORD PM VOLTAGE AT SEVERAL DIAGNOSTIC WAVELENGTHS. TURN N2 FLOW RATE TO 15L/MIN AND RECORD VOLTAGE AT 190, 253.7 AND 600nm USING A 2nm BANDWIDTH. It is important to keep a record of the lamp output to monitor decay of the far-UV signal and the alignment of the visible mirrors. Please note if you are using the peltier or standard sample holder as this affects the PM voltage. You may lower the N2 flow rate back down to 10L/min if you are no longer going to wavelengths below 200nm.

 

10) Power down-- Remeasure the pm voltage at the diagnostic wavelengths 190, 253.7 AND 600nm USING A 2nm BANDWIDTH. SHUT OFF THE CD MACHINE BY REVERSE ORDER OF THE POWER ON INSTRUCTIONS (i.e.. computer--exit program and turn off monitor, peltier and water bath, power 2, power 1, N2 tank). PLEASE RECORD ALL REQUESTED INFORMATION IN THE LOGBOOK INCLUDING:

         • TOTAL LAMP HOURS

         • STATUS OF N2 TANK

         • WHAT PARTS YOU USED (CUVETTES & SPACERS) AND HOW          YOU CLEANED AND STORED THEM.

 

         Every Logbook Entry should look like this:

 

                           3/17/99     Sheila Jaswal/Agard lab        6-9375

 

         lamp on     190            253.7                  600nm      

         10AM-        285.7         224.3                  290.6

         3PM            286.0         224.4                  290.8

         Total Lamp Hrs: previous sum + 5 hrs                     

         comments: used Agard 2mm cuvette, left in Nitric acid in hood,

                  left stopper in cuvette drawer, left spacer in sample compartment,

                  used peltier sample holder

                  N2 tank is ~3/4 full.

 

 ADDITIONAL NOTES ON OPERATION:

 

• N2 gas flow rates need to be increased as you move below 200nm, not so much to protect the optics, but to prevent O2 absorbance of the light (O2 absorbance decreases the amount of light that gets to your sample and increases the PM voltage rapidly). Jasco recommends 15L/min for operation from 185-200nm and 60L/min for work below 185nm. Please be conscious of N2 use and set N2 flow rate accordingly.

 

• When the HT (or PM) voltage is >800 you are not in the linear response region any longer. Data collected beyond this point is worthless and not a great idea for the health and well being of the PM tube.

 

• HT (or PM) voltage MUST BE LEFT IN AUTO AT ALL TIMES! If you have been trained on use of the machine out of this mode, you must leave the machine in auto mode. If you leave it out of auto and don't take care, you can ruin the PM and this would be very, very, very bad for you.

 

• Baseline choice in data acquisition menu is NOT for your sample baseline. Instead, it is to measure the intrinsic instrument baseline. You can use this baseline if you don't measure your own baseline.

 

• Any recalibration of the machine is to be done by a qualified personnel and will be noted in the logbook. If you feel that the machine is in need of recalibration, please contact a curator.

 

• The Jasco software will automatically name each spectrum recorded, starting with the filename noname00. You must save this data before you shut down the program, or the data will be lost. We recommend saving as you go to avoid losing data. You can retrieve saved data in STANDARD ANALYSIS mode (open FILE MANAGER-

->j715-->j7stdanal.exe.

 

OPTIMAL EXPERIMENTAL SETUP HINTS:

• Response time = 4X time constant (old Jasco uses the time constants) = the time required to reach 98% maximum signal.

 

• You should sample at least twice the frequency of the bandwidth.

 

• Scan speed is linked to response time. A rule of thumb given by JASCO in order to not clip peaks or waste time is:

 

         response time (sec) x scan speed (nm/min) < 200