Hi Temperature PIR Detection

bat

Well-known member
Joined
Jan 12, 2002
Messages
4,354
Reaction score
0
Got a few deer coming to my garden so I went to put my cam out behind it.  The temperature has been in the high 90's, close to 100 degrees here the last few days.. :sun-shining: boy is it hot.  Anyway when I put the cam in place and did the walk test.....nothing, hmmmm, tryed another cam, then another, all three would not detect my motion.  It was about 90 when I put it in place so I'm thinking the air temperature was so close to my body temp. that it would not pick up.  Anybody else seeing this?  Thanks!  bat
 



davered1

Well-known member
Joined
Sep 1, 2001
Messages
1,793
Reaction score
0
BAT,

I'll let you know maybe late AUGUST (if it even hits that here then) hardly ever gets that hot here!!
 

FLBowhunter

Well-known member
Joined
Jan 31, 2002
Messages
411
Reaction score
0
I have had a similar problem...I put out a camera and the test LED would only come on at a very close distance.  So I sat down to cool off and think about the problem and when I got back up the PIR seemed to be working better.  It was like it just needed time to acclimate to the heat.  I really don't know for sure...
-Scott-
 

bat

Well-known member
Joined
Jan 12, 2002
Messages
4,354
Reaction score
0
Thanks dave and FLBowhunter, that could be what it's doing.  I had all of them in the house where it was about 70 degrees and didn't stay out there long with either one of them.  Was getting dark so I wanted to get out of the area as quick as I could in case they were showing up early.  I will check them out more tomorrow...bat
 

wvhunter

Well-known member
Joined
Mar 11, 2001
Messages
817
Reaction score
0
Warmer air temps will decrease the range of the PIR.  I use the RS PIR and in temps over 90 the range will reduce to about 15-20 feet.
 

Archilochus

Well-known member
Joined
Mar 27, 2001
Messages
1,285
Reaction score
0
High temps can sometimes reduce range to almost zero.  Particularly if the air AND background temp are both near body temp.  Usually there is enough variation in temp within a large mammals body to cause the sensor to "see" a temp difference - but not always.
Try a shady spot that stays cooler than the air temp.

Archilochus
 

jayber

Well-known member
Joined
Aug 20, 2002
Messages
2,010
Reaction score
0
I recall that phenonmena happen a couple of times last summer when I was setting up cams.  Sometimes I would walk past and it would trigger, other times it wouldn't.  And it seemed that the distance was reduced.  I recalled the discussions regarding heat affect, but I left it out anyway.  I still got some good pics at a fair distance, all times of the day.  I'd just try one of yours and see what you get.  BTW, what sensor you using?
 

bat

Well-known member
Joined
Jan 12, 2002
Messages
4,354
Reaction score
0
Thanks for the replies guys, jayber I'm using a RS PIR.  Thanks for the tip about the shade Arch, I may have to back it up into his/her path a little if I can figure out just where its coming out of the woods.  I turned on my sprinklers to the peas about an hour ago and fresh mowed yard grass might bring the deer out tonight.  It's about 88 right now out there and the pir will pick up at about 28'.  It's suppose to cool back down some the rest of the week so "maybe" I'll get a shot at the deer.  Thanks again, bat  
 

bat

Well-known member
Joined
Jan 12, 2002
Messages
4,354
Reaction score
0
update,
 It has dropped back down to around 80 degrees a little while ago so I tested my pirs out again.  The one I just completed I had set up for a distance of about 13/16" to 7/8" from the fresnal lens and it detected out to 55' at this temperture.  Checked one of the others and it would not.  I backed the board up 1/8" and got it to pick up at 45', then moved it forward to 5/8" and it picked up at 51', ....much better than it was(20').  I know this is beyond the range of the flash but I am leaving it there to see what it does tomorrow when the temperture goes back up to 90 degrees.  
 bat

(Edited by bat at 11:16 pm on June 8, 2002)
 


Top Bottom