====== Problems and Solutions ====== ====== 2DC ====== ===== Problem (Spring 2012) ===== During the GCPEX project, the House keeping data all had digital number of approximately 1281. ===== Cause ====== The House Keeping card in the probe had an issue. Swapping out the 2DC housekeeping card with a similar one, everything worked. ===== Solution ===== Worked with WMI to replace the broken components on the card. ===== Problem ===== When doing a 2DC Spinning Disk Test, additional bits are being recorded in some of the images. See image below {{:atmos:citation:instruments:2dc:2dc_problem1.png|}} The following picture was taken at SEA, no problem was shown. See below: {{:atmos:citation:instruments:2dc:1-2011-12-15-131323.jpg|}} ===== Cause ====== Incorrect bit shift value. ===== Solution ===== We changed the bit shift value in the 2dc board table from 4 to 1. The value of .25 was also used; however, that seemed to make the problem worse, therefore we stuck with one. Below is the correct 2DC image: {{:atmos:citation:instruments:2dc:2dc_image.png|}} ===== Problem ===== On board #1 channel #20 (starting with 0) gave incorrect voltage reading on the M200 display compared to a volt meter. On board #1 channel #4 (starting with 0) would result in spikes so the pitot static wing measurement was moved to channel #0 during MPACE (Fall 2004) which result in no spikes or problems with the measurement ===== Cause ===== Something is wrong with some of the channels on the Analog to Digital Converter. ===== Solution ===== Board #1 was sent to SEA, Inc. for calibration in June 2005. At this time the board #2 was replaced with a new Analog to Digital Converter box since the one that was being used since August 2004 was only on temporal until a new box could be built. ===== Problem ===== Several of the channels were not working on the recently calibrated board #1. These channels were the same channels that did not work on board #2. ===== Cause ===== One of the channels was incorrectly reffering to another channel's formula in the fml.300 table The rest of the channels were incorrectly labeled in the buf.300 table. ===== Solution ===== Change the formula for the one channel to the correct formula. Change the names of the channels in the buff.300 table to match the names in the acq.300 table. ===== Problem ===== The end element voltages on the 2dc were very low ===== Cause ===== Dirty optics ===== Solution ===== Clean the windows in the 2dc probe arms and inside with isopropyl alcohol. October 14, 2010 Measured end voltages before cleaning. Channel 1 voltage is 1.69, bouncing around a little. Let stabilize for 3 minutes. Channel 32 voltage is 2.31. Cleaned the windows with isopropyl alcohol. Channel 1 voltage is 1.73 volts. Channel 32 voltage is 2.65. Prisms did appear dirty. Reinstalled probe back into canister. December 10, 2010 Powered up the probe in the canister useing the M300 to view end voltages. Observed low channels, ch.1, was at 1.67 vdc. High channels, ch.32 was at 2.07 vdc. Removed the 2DC from the cannister and brought it into the lab to bench test it. Without touching the optics, I measured ch.1 and it was 2.6 vdc, and ch.32 was 2.5 vdc. December 23, 2010 Performed a test on the 2DC probe to check voltages in and out of the canister. Observed some diffrences between the M300 voltage read-outs and the Fluke V.O.M. Before I removed the probe I observed the Low channel at 2.19 vdc, and High at 2.21 vdc. After removing and hooking the probe up to the cannister w/ the test extension cord, I read the Low channel at 2.19 vdc, and high at 2.40 vdc. After re-installation, I observed the Low channel at 2.27 vdc, and High at 2.10 vdc. When the probe was out I compared the M300 voltage vs. my Fluke V.O.M. The Low side read 2.70 vdc on the Fluke and 2.21 vdc on the M300. The High side read 2.74 vdc on the Fluke and High read 2.4vdc on the M300. ===== Problem ===== Noise in the 2d images that appeared only in half of the images. ===== Cause ===== Bad connections with the 2D cards in the probe itself. ===== Solution ===== Remove the 2D-C from the PMS can, remove the 5 cards at the end of the 2D-C, and clean the connections with acetone. April 20, 2011: Noise and false Shadow OR was observed on the 2D-C data during the ferry flight from UND to Ponca City, OK on April 19, 2011. Noise was observed in half of the 2D-C images during ground testing on April 20. Called DMT and the suggestion was to clean the connections on the 2D cards. Noise was drastically reduced after card connections were cleaned and reinstalled in probe.