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Entry  Fri May 7 16:51:09 2010, Frank, Lab Infrastructure, General, particle counter 
    Reply  Wed Jun 2 17:59:57 2010, rana, Lab Infrastructure, General, particle counter + lab temp 
Message ID: 794     Entry time: Wed Jun 2 17:59:57 2010     In reply to: 760
Author: rana 
Type: Lab Infrastructure 
Category: General 
Subject: particle counter + lab temp 


the manual how to use the particle counter is where the rest of the manuals are. If you want to use it read the manual BEFORE you touch it and reconfigure everything so that nothing is working anymore. If you still don't know how to use it or can't find the manual you can ask me or simply google for it. If you only want to read the latest values you don't have to program or even touch the thing at all. Simply connect it to a computer via serial port. Right now it is taking data every 10min or so for a short period of time. Up to 8000 measurements are stored in the device, starting to overwrite the oldest ones when reaching the limit.

The software is installed on the small laptop, the same we use for the WinCam. There is an icon on the desktop, i think the software is called "comet" or so. You have to connect the cable with the USB-to-serial adapter. The cable has a label "particle counter". Plug everything together,  run the software, and from the menu simply choose something like read everything, meaning data and settings. That's it.

Data is saved in comma-separated  textfile, using current date and time. Sometimes it happens that it can't plot the data later on because the data is corrupt. I don't know why this happens but it simply forgets some characters while reading from the serial port or saves it twice. As it is a simple textfile this is easy to fix.

 The Particle Counter is a GT-526 from Met One. Datasheet on the web here.

The manual is here.

I was unable to get the data off of it using my Mac and Terminal. I tried to get the data off of it using Frank's wonderfully helpful elog entry, but was still unable to. When retrieving data using the 'Comet' software on the little laptop, the window just says '0% complete' and continues counting. After 12 minutes, I gave up.


The setup of the counter seems to be that it adds up for 10 seconds and then waits for 590 seconds. The display on the front panel is in units of 'CF".

The current reading (while Alastair and I are working on the table) is:

0.3 micron     30000 CF

0.5 micron      3000 CF

1.0 micron      1700 CF

I'm assuming that we multiply by 6 to get to the commonly used CFM (# of particles per cubic foot per minute).

Around 5:30PM today, Alastair commented on how the 2 HVAC systems seemed to be fighting. Recently, the physical plant guys installed a second AC sensor (stay tuned for the elog and photos from Aidan). Apparently, these systems don't feed the same controller. So I decreased the temperature on the new South wall sensor by 1.5 F down to 68 F. The one in the NW corner of the lab is unchanged.

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