CACHE94: PROP Messages: 30 Entries..

Prop data rate changed to 1 hz: 
 
 The data rate at 5 hz was causing glitches. 
Looking at the message via rserial data were 
being lost. 
 

Data rate on props at 5hz: 
 
  The data rate on the props has been 
set back to 5hz to see how things work. 
Time: 17:35 gmt. 
 

Props back to 1 hz: 
 
 The props were set back to 1 hz. "rserial" 
shows a problem in the communication at the 
5 hz. Maybe having 6 sensors running at the high 
speed causes an overload in the Ironics. 
 

Prop Angles: 
 
 The prop angles as of 8/7/94: 
 
 prop (height)		   angle 
------------------------------------ 
 2.5			207 54' 18" 
 5.0			206 53' 10" 
 7.5			206 51' 50" 
10.0			206 51' 50" 
12.5			206 13'	40" 
15.0			205 13' 20" 
 
angles set in sensors: 
 
 2.5			207.9 
 5.0			206.9 
 7.5			206.9 
10.0			206.9 
12.5			206.2 
15.0			205.2 
 

Props changed to 5 hz at 21:20 GMT. 
 

Props set to 2hz 
 
The daisy serial card apparently cannot keep 
up with 6 props operating at 5 hz.  We'll 
try 2 hz.  Here are the current EEPROM parameters: 
 
	2.5m, daisy 202 
W:0004      6     2  1858  125 00u\n 
W:0004     21     7  1864  125 00f\n 
W:0004      0     0  1933  125 00C\n 
W:0004      0     0  2038  125 00F\n 
Q\n 
Parameters \n 
     Sample rate = 250 Hz\n 
     Xmit rate   = 0125 samples\n 
     Boom align  = 406  counts\n 
     Boom angle  = 207.9 degrees\n 
     True North  = 110  counts\n 
     Prop Pitch  = 301  mm/rev\n 
W:0004     12     4  1719  125 00j\n 
W:0004     21     7  1658  125 00e\n 
W:0004     24     8  1664  125 00d\n 
W:0004     24     8  1679  125 00^\n 
 
	5m, daisy 203 
W:0003     87    29  1007  125 00R\n 
W:0003     87    29  1089  125 00H\n 
W:0003     78    26  1169  125 00L\n 
W:0003     78    26  1252  125 00S\n 
Q\n 
Parameters \n 
     Sample rate = 250 Hz\n 
     Xmit rate   = 0125 samples\n 
     Boom align  = 009  counts\n 
     Boom angle  = 206.9 degrees\n 
     True North  = 227  counts\n 
     Prop Pitch  = 301  mm/rev\n 
W:0003     87    29  1263  125 00N\n 
W:0003     81    27  1176  125 00S\n 
W:0003     75    25  1093  125 00T\n 
 
	7.5m, daisy 204 
W:0001    225    75  1536  125 00B\n 
W:0001    189    63  1574  125 00z\n 
W:0001    186    62  1708  125 00\0x7f\n 
Q\n 
Parameters \n 
     Sample rate = 250 Hz\n 
     Xmit rate   = 0125 samples\n 
     Boom align  = 199  counts\n 
     Boom angle  = 206.9 degrees\n 
     True North  = 417  counts\n 
     Prop Pitch  = 301  mm/rev\n 
W:0001    168    56  1484  125 00 \n 
W:0001    210    70  1403  125 00T\n 
W:0001    243    81  1604  125 00I\n 
 
 
	10m daisy 205 
W:0002    319   106  1547  125 00p\n 
W:0002    340   113  1566  125 00w\n 
W:0002    331   110  1595  125 00x\n 
Q\n 
Parameters \n 
     Sample rate = 250 Hz\n 
     Xmit rate   = 0125 samples\n 
     Boom align  = 351  counts\n 
     Boom angle  = 206.9 degrees\n 
     True North  = 057  counts\n 
     Prop Pitch  = 301  mm/rev\n 
W:0002    394   131  1571  125 00r\n 
W:0002    370   123  1565  125 00t\n 
W:0002    376   125  1612  125 00s\n 
 
	12.5m daisy 206 
W:0007    352   117  1602  125 00t\n 
W:0007    370   123  1612  125 00v\n 
W:0007    343   114  1554  125 00q\n 
Q\n 
Parameters \n 
     Sample rate = 250 Hz\n 
     Xmit rate   = 0125 samples\n 
     Boom align  = 343  counts\n 
     Boom angle  = 206.2 degrees\n 
     True North  = 050  counts\n 
     Prop Pitch  = 301  mm/rev\n 
W:0007    379   126  1500  125 00n\n 
W:0007    397   132  1494  125 00e\n 
W:0007    415   138  1518  125 00k\n 
 
	15m daisy 207 
W:0006    249    83  1737  125 00u\n 
W:0006    255    85  1734  125 00y\n 
W:0006    261    87  1697  125 00r\n 
Q\n 
Parameters \n 
     Sample rate = 250 Hz\n 
     Xmit rate   = 0125 samples\n 
     Boom align  = 467  counts\n 
     Boom angle  = 205.2 degrees\n 
     True North  = 175  counts\n 
     Prop Pitch  = 301  mm/rev\n 
W:0006    264    88  1672  125 00u\n 
W:0006    231    77  1685  125 00y\n 
W:0006    231    77  1702  125 00C\n 
 
 
 
 

Prop/Vane Xmit rate changed to 1Hz 
 
All anemometers were changed from 1/125 samples to 1/250 samples 
for the message output rate (i.e. 2Hz to 1Hz). 
Effects daisy: 202-207. 
 

Swapped Props at 15-m with 2.5-m 
 
Wind sensor id 6 has been continuing to consistently glitch 
despite reducing the message output rate yesterday from 2Hz to 1Hz. 
 
Swapped it with sensor id 4 which has been running OK at the 2.5-m 
location.  Will keep an eye on it, but at least it'll be easier 
to get to. 
 

15m propvane speed out 
 
Propvane wind speed at 15m is 
out. Direction OK. 
 
Heavy rains last night. 
 
 

Repair work on props and psychrometers. 
 
We just completed work on both towers. 
 
Psych. 
 We noticed all humidity values to be abnormally high, and 
found out that the humidity sensor shield, gore-tex filter were soaked 
with water on most units. We tried drying them, but later decided a 
better long term solution would be to remove the filters altogether. 
This way, even though the sensor might get wetter during rain/high 
humidity events, they will be able to dry out sooner. 
 
Anemometer 
The 15 meter anemometer was reading consistently low, we brought it 
down for inspection and found out that the nut holding in the propeller 
was loose, and hence the propeller would spin without full transfer to 
the shaft. 
Action taken, tightened nut and remounted the anemometer. 
 
Data from 17 to 19 GMT should be suspect, as well as data from the 
sensors in question for the last 2 days. 
 
SN 
 

Prop tower 15m anemometer replaced 
 
The 15m anemometer was still reading a bit low consistently, 
hence it was exchanged with the 2.5m unit. 
Data at 15m looks normal now. 
Expect the usual dropouts at about 00:10 GMT, 
plus a lower than expected reading for the 
2.5m anemometer now. We'll see what we can do 
about that tomorrow. 
 

15m propvane has come back to life 
 
The 15m propvane, which was reading 
low yesterday, appeared to come 
back into range this morning. We have 
been seeing a monotonic profile 
since about 1400. 
 

I just removed it for inspection, since it has been reading
low.

The 2.5m propvane had a little moisture in ti. It
is not obvious why this would cause it to read
low. Santiago dried it out, and we reinstalled it.
It appears to be reading correctly now.

The speed on the 2.5m propvane has gone bad again. It
is reading very low; spinning the prop by hand gives 
at most less than a meter per second.

Perhaps the problem is a temperature dependence.
Temps are generally cooler now than they have been
for a long time.

The 15m propvane has been reading low 
for several days now, although it did
show a few periods of realistic peformance.
We moved the unit at 5m (serial no 3) up to
the 15m height, and the 15m unit (serial no 6)
down to the 5m height.

We exchanged the 15 meter anem. which read low, with the 5 m. unit.
When we reinstalled the 15 m. unit in teh 5m. slot, we found out
that it had died. Post-mortem revealed lots of water inside the
serial interface enclosure. Drying everything out very well, produced
the expected results.
We have reinstalled the unit on the tower, and for the first time
in a while the entire wind profile looks good.

The 5 meter anemometer stopped.
Cause? The pulley string from the nearby PSYCH  tower had gotten loose,
and in the high wind, blown across and wrapped itself around the propeller,
some 20 times!
If anything can go wrong...

All it took was some showers and cool humid air, and
we're back to very low readings, even though I see the prop
spinning about as fast as the 5 m unit.
Serial # 004 is definitely a lemon!

Removed 15m prop vane from tower at 1100 PDT because the wind speed
output was very low.  Disassembled the wind speed head and found water
between the outer shell of the wind speed encoder and its mounting
projection from the wind vane, in front of the o-ring seal.  Tried to 
improve the seal by adding silicone grease.  Also found water inside
the main processor enclosure, so sealed that area with RTV per Charlie's
suggestion.  Replaced unit (#3) on prop tower at 1715 PDT.

Realigned 15 m prop vane with alignment fixture.  

Boom alignment changed from 009 to 012 counts
Reset boom angle from 206.9 to 205.2
True North changed from 227 counts to 232

Noticed that the 5m prop had a strange boom angle of 3276.7,
although the data look reasonable.  However also realigned 5 m prop:

Boom alignment changed from 467 to 483 counts
Re-entered boom angle of 206.9
True North changed from 173 to 189 counts

Based on the mean wind speed profile and on the profile of the wind 
speed variance, the 10 m prop speed output appears to be dying.

The 15m wind direction has been bad since mid day yesterday.  We found
that the vane was loose on its shaft, so tightened the set screw and 
realigned it relative to the boom.  This process changed the boom
alignment from 012 counts to 232 and true North from 413 counts to 121.
Gordon also found that the 15m vane could now strike the nearby guy 
wire and that the guy wire was rubbing on the top of the hauling boom.
He pulled the guy wire away from the path of the vane with a piece of 
rope tied to the tower and lowered the hauling boom a few inches.

The 5m speed has also been dropping out periodically, so removed prop
from the tower.  In the process, water ran out of the bottom of the
vertical shaft.  Disassembled and found that speed board was dry, but
the serial board enclosure had considerable liquid water in it and the
non-component side of the serial board was corroded.  Cleaned board 
with alcohol.  Also fixed broken leads on 20 pin serial board connector.
Reassembled unit, sealing as before with RTV and silicone grease and
inserting new dessicant packs.  Realigned wind vane: boom alignment 
changed from 483 counts to 482, true North changed from 189 counts to 188.
Remounted on tower at 5m at about 7:15 pm PDT.

Took down 2.5 meter prop (ID=4) which was giving low wind speeds.  9:00am PDT

Liquid water was present in the chamber containing the main PC board.
The speed encoder chamber seemed dry.  

Sealed all joints with silicon caulk, greased o-rings in speed encoder
chamber with silicon grease. (The silicon grease is rated from -40 to 400
deg F, so it shouldn't melt into the speed encoder at high temperature.)

Put 2 dessicant packs in main chamber.

Checked boom align and boom angle settings with boom alignment tool - all OK.
 

The 7.5m prop has stopped transmitting data.  Recycled power twice, but
no response.  Removed from tower and disassembled.  Serial board enclosure
was very wet, but wind speed board was dry.  Cleaned corrosion off pin
(non-component) side of serial board.  However was apparently too ignorant
to establish serial communications with board in order to check it out.

Changed baud rate on terminal to 9600 and 7.5m prop checked out okay
on bench.  Reassembled, lubri-sealing as previously.  Checked boom
alignment and unchanged (boom align=199 counts, true North=417 counts).
Remounted at 7.5 m.  This is prop #01.

Note that 2.5m prop has stopped transmitting wind speed.

At roughly 16:15, intense winds removed the pulley from the hauling boom
atop the profile tower.  The rope became entangled with the 7.5m and 10m
prop-vanes, and did some damage:  the 10m vane has is shredding and making
loud flapping noises in the wind.  The 7.5m prop lost a blade, and the 7.5m
vane is not in the best of conditions, either.

Tris and Andy disengaged the rope from the instruments, and took it to the
bottom of the tower, at around 16:18.

It appears that only the 7.5m and 10m instruments were affected.


16:25 update:  now the wind has ripped the 10m tail fin completely off, 
and the 7.5m fin seems sure to follow it down the slope, since the fin is
flapping loudly in the intense wind.

Within an hour, both tailfins were ripped off, and the ensuing orientation
of the props (with the propellors downwind of the vanes) unscrewed the props
from their mounting nuts, allowing the props to fly off the instruments and
down the slope as well.



Howling easterlies!

The 7.5m and 10m prop-vanes self-destructed yesterday (JD264) sometime
after 1600 GMT.  According to Andy, the hauling rope tangled in the vanes
so that they could not orient into the wind and subsequently the vanes
ripped off.  Then the props oriented themselves backwards to the wind
and the wind heads screwed themselves off!  The hauling rope apparently
detached from the boom because the string holding the pulley failed.
See earlier entry 355 for eye-witness account.

The 12.5m vane looks a little twisted as well.

Moved the 5m prop to 10m and the 2.5m prop to 7.5m.  Both operating by
12:45 pm PDT.  Changed boom angle from 207.9 to 206.9 on new 7.5m prop
(#04).  True North changed from 364 to 366.

At about 18:05 GMT the DC power to the 4 remaining props was inadvertantly
disconnected for about 5 minutes.