Equipment Photos
Jan. 26th, 2005 03:03 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
revchrisSome days my job can be a real challenge.
I've got an xray analysis instrument that we've been working on repairing since July. After a lot of work, and being sent to the factory one, I'm down to confirming the alignment & calibration, which, while straightforward in the directions, is a real bear to get right.
On top of that, on of the profs wants to use the machine for class (not unexpected, since that's why we bought it). Unfortunately, he doesn't believe me when I tell him how some part of it works, so I wind up explaining things over and over. Yesterday, he wanted me to set up a demonstration to show students what the beam looks like whan it hits a target sample.
That's the hardest thing to demonstrate for students. To do so, you have to override the safety interlocks so that you can run the system with the enclosure open (mostly because the enclosure is gray plexi and you can't see through it well enough). Then you have to make the room dark. This mean covering every source of light, including the LEDs on the GFCI outlets. I generally leave a few of the red lights around the room on, but you have to cover all of the green and white light sources so that you have all of your green receptors available. Finally, you turn on the machine, and let them stick there heads inside the enclosure because the beam on the phosphor target is still really dim.
This just sounds like a bad idea with students or professors.
I decided, instead, to try to take a picture.
Now, I have to figure out how to get a digital camera to focus correctly, and to take a long enough exposure, in a pitch-black room.
Fortunately, my camera has manual focus. So, I set it for an 8 second exposure (the longest I can make it do without looking in the manual), manually focus, turn off the lights, go back to the camera to hit the shutter, kick the tripod by accident, turn the lights back on, find a flashlight, set everything back up, turn the lights off, and then start taking pictures and trying things to make it all show properly.
The green line, in reality, is dim enough that the light from the LCD display on the camera, looking at the blackness that is my subject, is still bright enough to interfere with seeing it.
35 shots later, the final solution was to change the parameters for the machine to let a larger multiple-frequency beam through, start the exposure, then trigger an external flash (set for its 1/16th power mode) pointed away from the system.
This is the result
Now, I have to go back through the system and figure out where I shifted the alignment, because the green bar is supposed to be centered on the grayish circle (the x-ray phosphor in the sample holder). I also want to get a better picture, since there really should be three green lines, one much brighter than the other two, representing the K-alpha-1, K-alpha-2, and K-beta copper xray frequencies.
I've got an xray analysis instrument that we've been working on repairing since July. After a lot of work, and being sent to the factory one, I'm down to confirming the alignment & calibration, which, while straightforward in the directions, is a real bear to get right.
On top of that, on of the profs wants to use the machine for class (not unexpected, since that's why we bought it). Unfortunately, he doesn't believe me when I tell him how some part of it works, so I wind up explaining things over and over. Yesterday, he wanted me to set up a demonstration to show students what the beam looks like whan it hits a target sample.
That's the hardest thing to demonstrate for students. To do so, you have to override the safety interlocks so that you can run the system with the enclosure open (mostly because the enclosure is gray plexi and you can't see through it well enough). Then you have to make the room dark. This mean covering every source of light, including the LEDs on the GFCI outlets. I generally leave a few of the red lights around the room on, but you have to cover all of the green and white light sources so that you have all of your green receptors available. Finally, you turn on the machine, and let them stick there heads inside the enclosure because the beam on the phosphor target is still really dim.
This just sounds like a bad idea with students or professors.
I decided, instead, to try to take a picture.
Now, I have to figure out how to get a digital camera to focus correctly, and to take a long enough exposure, in a pitch-black room.
Fortunately, my camera has manual focus. So, I set it for an 8 second exposure (the longest I can make it do without looking in the manual), manually focus, turn off the lights, go back to the camera to hit the shutter, kick the tripod by accident, turn the lights back on, find a flashlight, set everything back up, turn the lights off, and then start taking pictures and trying things to make it all show properly.
The green line, in reality, is dim enough that the light from the LCD display on the camera, looking at the blackness that is my subject, is still bright enough to interfere with seeing it.
35 shots later, the final solution was to change the parameters for the machine to let a larger multiple-frequency beam through, start the exposure, then trigger an external flash (set for its 1/16th power mode) pointed away from the system.
This is the result
Now, I have to go back through the system and figure out where I shifted the alignment, because the green bar is supposed to be centered on the grayish circle (the x-ray phosphor in the sample holder). I also want to get a better picture, since there really should be three green lines, one much brighter than the other two, representing the K-alpha-1, K-alpha-2, and K-beta copper xray frequencies.
