Learning how to take light measurements with a DMM

I had that in my cart before I found the almost-free HF ones work adequate enough to bother clicking buy on it. I didn't get the other cheapos because they didn't have backlight (and equus doesn't either but it's got the big lcd). Go for it.

Now when I get me another meter to replace the one I broke I will keep learning and go from there. Oh well glad it was a cheap meter and not a $200 Fluke.

I think you didn't set the dmm to 10AA. I did that myself once ( a long time ago)

Not that a Fluke can't be smoked, but you do have to try pretty hard.

I'm amazed at the blunders I've done and my Fluke has survived. (Like leaving it on continuity while I'm checking the output of a power supply.)

For some fun check out www.eevblog.com/2010/05/05/eevblog-84-high-energy-multimeter-destruction/ its about 12 minutes long and is quite entertaining.

I just got this guy in the mail today:

http://www.amazon.com/Equus-3320-Auto-Ranging-Digital-Multimeter/dp/B000EVYGZA/ref=sr_1_17?ie=UTF8&qid=1308712950&sr=8-17

I now know what I did wrong before so now I can learn by playing with my Solarforce L2p. :)

Bad news, that meter maxes out at 200ma or .2 amps your XML lights pull over 3 amps or 3000ma. So if you try to measure amperage you will melt that meter or pop the fuse if it has one. I am a mechanic so I bought a Fluke 179 for work and when I popped the fuse it cost $12 dollars for just the fuse. I am sure someone will chime in with a budget meter that will do what you want it to.

eeerrr, hmmm that is not good. Well here I was thinking I was making a good choice. LOL :) Hmmm, now what? LOL Here are the specs from the manual:

SPECIFICATIONS
GENERAL SPECIFICATIONS AND FEATURES

3-1⁄2 digit LCD display (maximum reading of 2000); 3 LEDs;
green, yellow and red
Auto Range (ACV, DCV, Ohm, AC mA, and DC mA)
Automatic negative (-) polarity indication
Automatic zero adjustment
Over range indicator (except 10 A function). Displays "OL" on
LCD
Low battery indicator. Displays battery symbol
on LCD
Automatic power shut off (after 15 idle minutes)
Pollution Degree 2
Measuring circuit category II
Operating environment:
Temperature - 32° to 104° F. (0° C to 40° C)
Humidity - Less than 80% relative humidity (non-condensing)
Altitude - up to 6562 ft (2000 meters)
Storage environment:
Temperature - 4° to 140° F (- 20° to 60° C)
Humidity - Less than 90% relative humidity (non-condensing)
Power Supply: Two 1.5V AA batteries
Fuse: 315mA/250V 5X20 mm (Radio Shack, GMA/217
series; #270-1046) fuse
Dimensions:
Height - 5.50 in. (139 mm)
Width - 3.50 in. (89 mm)
Depth - 1.25 in. (32 mm)
Weight (including batteries): approximately 6.3 oz (180 g)
ELECTRICAL SPECIFICATIONS
DC VOLTS
Range Resolution Accuracy
200.0mV 0.1mV
2000V 1mV
20.00V 10mV
200.0V 100mV
600V 1V
3
E
Notes
±(0.8% of Input Resistance: 10MΩ
reading
Overload Protection: 600V DC
+ 5 digits) or AC 600V RMS.
AC VOLTS
Range Resolution Accuracy
2.000V 1mV
20.00V 10mV
200.0V 100mV
600V 1V
Notes
Input Resistance: 10MΩ
±(1.2% of Overload Protection: 600V DC
reading
or AC 600V RMS.
+ 5 digits) Frequency Response:
50Hz - 400Hz
RESISTANCE (OHMS)
Range Resolution Accuracy
200.0Ω 100mΩ
2000kΩ 1Ω
20.00kΩ 10Ω
200.0kΩ 100Ω
2.000MΩ 1kΩ
20.00MΩ 10kΩ
Notes
±(1.0% of
Overload Protection: 250V DC
reading
+ 5 digits) or AC RMS.
±(2.0% of
reading
+ 5 digits)
DC AMPS
Range
Resolution Accuracy
Notes
±(1.0% of Overload Protection: Fuse
reading
315mA/250V
200.0mA 100μA
+ 5 digits) Input Voltage Drop: <0.2V.
±(2.0% of Unfused; 15sec maximum
2.000A
1mA
reading
Input Voltage Drop: <0.2V.
*10.00A 10mA
+ 5 digits)
*A waiting period of at least 15 minutes is necessary between
every 15 second testing period.
20.00mA 10μA
AC AMPS
Range
Resolution Accuracy
Notes
20.00mA 10μA
±(1.5% of Overload Protection: Fuse
200.0mA 100μA
reading
315mA/250V
+ 5 digits) Input Voltage Drop: <0.2V.
4
E
BATTERY TEST (LEDs)
When the voltage of the battery being tested is lower than
10% of its rated voltage, the red LED will not light.
Load
Range Resolution Current Accuracy
1.5V 0.001V 10mA
(approx.)
6V 0.01V 100mA
(approx.)
9V 0.01V 10mA
(approx.)
12V 0.01V 200mA
(approx.)
Notes
Green LED: 1.30V
±0.075V and up.
Yellow LED: 0.94V
±0.075V to 1.29V
±0.075V.
Red LED:0.15V±0.075V
to 0.93V±0.075V
Green LED: 5.22V
±0.3V and up.
Yellow LED: 3.76V
±0.3V to 5.21V±0.3V.
Red LED:0.6V±0.3V to
±(5% of
3.75V±0.3V
reading
+ 5 digits) Green LED: 7.83V
±0.45V and up.
Yellow LED: 5.64V
±0.45V to 7.82V±0.45V.
Red LED:0.9V±0.45V to
5.63V±0.45V
Green LED: 10.44V
±0.6V and up.
Yellow LED: 7.52V
±0.6V to 10.43V±0.6V.
Red LED:1.2V±0.6V to
7.51V±0.6V
DIODE/CONTINUITY TESTS
Function Range Resolution Description
Diode Test 2V
1mV
Test Current:
1±0.6mA
Test Voltage:
Approx. 1.5V
Continuity 200Ω
Test
5
E
0.1Ω
Note
Overload
Protection:
Approx. 120Ω or 250V DC or
AC RMS
less, buzzer
(beeper) will
sound

OK I think I was wrong I was reading a review that said 200ma max but I see a DC 10A selector in the picture so you should be good . Set the knob to DC10A put the red wire into the one marked DC10A and black to ground and test away.



That's for AC current measurements.

added: I replied before I saw your last msg.

That is a really nice meter for $16 bucks I might have to pick one up to leave in my tool bag in my truck. Great find have fun with it.

OK sweet, I am glad that I have a quality DMM now. :) I am looking forward to having fun with it and learning. OK here goes:

Solarforce L2p Host

5 mode XM-L drop-in

Trustfrie Flame 18650 cell @ 4.04 volts

Current consumption Test

Low= .083amps

Med= .835amps

Hi = 1.95amps

Alright, so now that I have this, what do the numbers tell me about the light?

Use this chart and what you know about the emitter to convert to approximate lumens.

http://flashlight-wiki.com/Brightness_Bins

Your Solarforce is an XM-L emitter T-6 bin at 1.95 amps approximately 650 lumens on high.

You might get a higher maximum readings if the battery is freshly charged.There is some lumen loss due to the lens not being 100% transparent and other factors.

The light that I got in mail today from Manafont:

Ultrafire 504B host

Ultrafire 3 mode XM-L T6

4.12v 18650 cell

this setup gave me these numbers for power consumption

Low= .05 amps

med= .38 amps

hi= 1.1 amps

You must have a deadish battery or the worse T6 in existence since that's DD. Or MF total changed their drop-in.

I have half a dozen of those drop ins and 4 504Bs and they all pull over 3 amps on high so you have a problem someplace.

Your batteries may not be good, what batteries are you using?

The leads to your DMM may be to thin to accurately measure higher amperage.

There may be resistance issues with the host (dirty threads etc. causing to much resistance measurable in Ohms) but that is doubtful.

Maybe you got a bad drop in, is it brighter then the one Foy sent you?

You should get numbers like this

High 3.4

Medium 1.0

Low .17

Those sound like numbers from an R2 drop maybe they sent you the wrong one.

The screw on reflector reads "Super Bright XM-L T6 4.2v" it came in an Ultrafire packaging with no marking on it as to what was inside. I am going to charge that Flame battery that Foy sent me in the Solarforce and try this again. The new XTAR 18700 cells I ordered will not fit in that Ultrafire 504B host, their diameter is too large....it wants to peel the stickers off the battery. The only other 18650 cells I have came from a guy on CPF who sold me a flashlight that I do not have any longer. They are Ultrafire 3000Mah cells....the red ones.

Simpleman, don't let it make you crazy going for measurements. Many of mine will pull 2.5-3A at the tailcap, and I was very disappointed in my vshark light, because it only pulls 1 amp.

But guess what? It is the one I have sitting on my nightstand. It still is blinding in the middle of the night, and at a 1A draw batteries last 3x as long in it as a 3A draw. It is nice to handle and tailstands beautifully, so I have no complaints about it.

That sounds like the right description of the drop in you ordered.

Without a good fully charged battery you are not going to get good readings.

I don't have any Xtar batteries so I don't know what the deal with that is. I have a bunch of the Trustfire flames and some of these Samsungs that are a smoking good deal.

I bought the XTAR 18700s from the group by because I was told they were a great battery at a smokin' price, so I have two red Ultrafire 3000Mah, one Flame 2400 cell, and four of the XTAR 2600Mah cells. :)

So basically you only have one good battery you can use in your new light.