Review of the Sper Scientific Pocket Laser Power Meter # 840011

This product does not emit light of its own (much like this spectrometer and this one), so the standard review format will not be used and the product will be assigned a rating at once. A very high rating too, as during the time I've had it, it has thus far performed flawlessly.

The Sper Scientific Pocket Laser Power Meter # 840011 (hereinafter, probably referred to as a "Laser Power Meter") is a small, pocket-sized instrument that allows you to measure the power output of pretty much any CW (continuous wave) laser with wavelengths ranging from 400nm (violet) to 1,100nm (near-infrared).

It features a silicon photodetector calibrated to the 632.80nm HeNe (helium neon) laser line, and can measure power output from 1µW (microwatt) to 40.0mW (milliwatts) at that wavelength; though the shorter in wavelength you go, the greater the laser power output you can measure - clear up to 400mW (0.40 watt) at 400nm in the violet part of the visible spectrum.

Accuracy is published at +/-5% @ calibrated wavelength of 633 nm / 1mW.

The unit uses two SR44 silver oxide button cells; since purchasing the product in late-2004 and taking no fewer than a thousand measurements, I have yet to change them!!! (Two LR44 alkaline button cells can be used in an emergency; but you really do need to find those SR44 silver oxide cells as quickly as you can).








To take a measurement, open the lid, and turn that large dial near the center of the instrument so that the arrow on it points to the maximum amount of laser power output you expect; if you're not certain, just set it to the 40mW scale -- you can always turn the dial to a lower range during your measurement if necessary.

You'll see a wand connected by a coily black wire, On the face of the wand near the top, you'll see a small black disc. Direct (aim) the laser beam at this disk, and note the reading on the unit's display. Write it down if necessary -- you'll soon see why.

To turn the instrument off, turn the large knob clockwise or counterclockwise until it stops.

On the inner surface of the lid, you'll see a table containing wavelengths (in nanometers) and values that need to be multiplied. Input your laser's wavelength in nanometers (ex. "532" for a green DPSS, "473" for a blue DPSS, etc.) into a calculator, press the "X" key, then look up your laser's wavelength on the lid and input the multiplier value into your calculator. When you press the "=" key on it, your laser's output power in milliwatts will be displayed.

If you're measuring a HeNe laser with a wavelength of 632.8nm (orangish-red), you may omit all of this and obtain your power output value directly from the display on this instrument.

You may "freeze" the laser's minimum or maximum power output values on this instrument by pressing the button on its left side (it looks like a door latch mechanism - but trust me, it's not).
Press and release it once to capture the minimum power output value; press & release it again to capture the maximum power output value; press & release it a third time to place the instrument back in its normal state.

TEST NOTES:
Test unit was purchased on Ebay sometime in late-2004.
It is still being sold as of late-February 2011, so I believe it to be germane here.



UPDATE: 00-00-00






MANUFACTURER: Sper Scientific
PRODUCT TYPE: Laser power meter
LAMP TYPE: N/A
No. OF LAMPS: N/A
BEAM TYPE: N/A
SWITCH TYPE: N/A
CASE MATERIAL: Plastic
BEZEL: N/A
BATTERY: 2x SR44 silver oxide button cells
CURRENT CONSUMPTION: Unknown/unable to measure
WATER- AND PEE-RESISTANT: No
SUBMERSIBLE: NO WAY HOZAY!!!

ACCESSORIES: Batteries
COUNTRY OF ORIGIN: United States
WARRANTY: 5 years


PRODUCT RATING:

This was one of my first meters. I later used an ND filter to increase the range.
No one would want this now because of its low power range.

HMike