Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Laser Pointer Store

LPM Help

Hap

Super Moderator
Staff member
Joined
Sep 5, 2013
Messages
8,443
Likes
1,584
Points
113
I just received the Radiant LPM from the guy on eBay but there seems to be a problem, which I think is me not setting it up correctly.

For some reason, the LPM(even with the dial turned all the way to make it go down) won't reach .000 and stays a few numbers above it. I've turned on the AC and that seemed to help bring the reading down, but it still isn't on .000

Is there anything else I should do?



-Alex
 

Joined
May 14, 2013
Messages
3,798
Likes
505
Points
0
Don't turn on the AC, no heater, no fans, be sure windows are closed and the air is still, no heat source nearby, even a lamp, even your hand close to the sensor can be 1 or 2mW.

Alan
 

Hap

Super Moderator
Staff member
Joined
Sep 5, 2013
Messages
8,443
Likes
1,584
Points
113
Ok, thank you guys I'll give it another go later today :)

@Bowtie just realized that haha.

-Alex
 
Last edited:

Hap

Super Moderator
Staff member
Joined
Sep 5, 2013
Messages
8,443
Likes
1,584
Points
113
Ok, I gave it another go this time in a loft with no fans, no lamps, no windows open and the reading still shows -.005/-.006

Anything else I could try? Does the room need to be at a certain temp possibly?

-Alex
 
Last edited:

chipdouglas

Well-known member
Joined
Dec 23, 2008
Messages
4,011
Likes
190
Points
63
I don't have experience with your meter. if you're trying to read a laser that is
in the hundreds of milliwatts, who cares if your off by so few mW.

just food for thought

Michael.
 

APEX1

New member
Joined
Mar 17, 2015
Messages
1,120
Likes
113
Points
0
honestly dude its not that far off! those tec sensors pick up he tiniest of things
 
Joined
May 1, 2011
Messages
1,063
Likes
107
Points
0
The potentiometer on those are bad. You gotta replace it. (That's the little rotating thingy on the top)
 

Cyparagon

Well-known member
Joined
Sep 12, 2007
Messages
9,520
Likes
1,044
Points
113
What does it read with the pot fully clockwise? What does it read with the pot fully counterclockwise?
 
Last edited:

Hap

Super Moderator
Staff member
Joined
Sep 5, 2013
Messages
8,443
Likes
1,584
Points
113
@Cyparagon

With it fully clockwise it reads -.003(at its highest). With it counterclockwise it reads -.011(at its lowest)

-Alex
 

Cyparagon

Well-known member
Joined
Sep 12, 2007
Messages
9,520
Likes
1,044
Points
113
You have 3 choices: Live with it, learn how to solder in a resistor, or send it to someone else that can solder in a resistor.
 

Hap

Super Moderator
Staff member
Joined
Sep 5, 2013
Messages
8,443
Likes
1,584
Points
113
I'll just deal with it, I'll add the power this LPM shows on lasers & add whatever the number below 0 was.

Thanks for the help!

-Alex
 
Last edited:

ARG

New member
Joined
Feb 27, 2011
Messages
6,987
Likes
575
Points
0
The Alpha's didn't have a differential (+/-) supply voltage, so in some conditions they don't settle down to 0. Only thing to do with it is solder in some components to fix it, or subtract the zero'd reading from the measurement.
 

Hap

Super Moderator
Staff member
Joined
Sep 5, 2013
Messages
8,443
Likes
1,584
Points
113
The Alpha's didn't have a differential (+/-) supply voltage, so in some conditions they don't settle down to 0. Only thing to do with it is solder in some components to fix it, or subtract the zero'd reading from the measurement.
Thanks for chipping in ARG, I'll just subtract/add the measurements when I measure lasers! Not too bad of an LPM for $42.99 :yh:

-Alex
 

Lifetime17

Well-known member
LPF Site Supporter
Joined
Dec 15, 2014
Messages
4,513
Likes
1,230
Points
113
Hi. might have to be calibrated reset to zero possibly. Just a hunch thats what it sounds like to me any way. Buti could be wrong or right good luck hey i wouldn't worry to much with that minor fluctuation just deduct the overage mW at the end of your test.. Best to you and your new LPM at least you have one buddy a lot of folks don't have that advantage.

sorry Arg scrolled down past your comment same same :))
 
Last edited:




Top