After the Sikorksy II field project the TDL instrument was sent in to get a new calibration. A TDL calibration check was done on July 5, 2005 and a TDL leak check was done on July 6, 2005. During the leak check, the TDL was pump up to 6 in Hg and watched until it drop to 5 in Hg. Total time to drop was 1 minute. After these test, the TDL would not output any water vapor concentration numbers.

The PC/104 CPU Module (RTD Embedded Technologies, CMM686GX233) inside the TDL was connect to a external monitor and keyboard. During the boot process the TDL gives the following:

Verifying DMI Pool Data ……… Disk Boot Failure, Insert System Disk and Press Enter

So it seems that the disk-on-chip (DOC) is bad and we need to replace it with a new one.

Order two new DOC and Randy May upload the DOS and PC-Anywhere software onto the chips. Replaced the old DOC with a new DOC. After the system booted into DOS (see notes below) created a H2O directory and uploaded the latest TDL file using PC-Anywhere. TDL worked like it did before the DOC problem.

Issues with replacing DOC in the TDL:

• The DOC is really on a socket and can be removed using a screwdriver to pry up on the Chip.
• The new DOC would not boot until a monitor and keyboard was connected to the PC/104 Module and it was noticed that it wanted a computer name to be entered. TDL was used as the computer name. After the computer name was entered it would boot straight into DOS.
• The new large monitor for the M300 would not work as a display for the M300. Used the old Viewsonic VG150 monitor.
• If the keyboard cable was connected backwards the TDL system would not boot. The keyboard cable has to have the white tab facing to the back of the TDL.