The meter in your link measures Lux not Lumens so a conversion is needed to convert from one to the other.

Most light meters measure LUX and to find the lumen measurement you need to do a conversion calculation to lumens.

Some LUX meters have a conversion button which is very helpful and are only slightly higher in price than a straight LUX meter.

**The difference between LUX & Lumens & how to convert LUX to Lumens**

Light intensity measured on a plane at a specific location is called illuminance. Illuminance is measured in footcandles, which are workplane lumens per square foot. You can measure illuminance using a light meter located on the work surface where tasks are performed. Using simple arithmetic and manufacturers' photometric data, you can predict illuminance for a defined space. (Lux is the metric unit for illuminance, measured in lumens per square meter. To convert footcandles to lux, multiply footcandles by 10.76 this is the easy way to convert).

Here is a link to a LUX to Lumen calc -

http://www.ledstuff.co.nz/data_calculators.php
If converting from LUX to Lumens the LUX to Lumen calc is the easiest way to do the conversion, unless your a maths wiz who loves to work things out.{serious maths, I wouldn't bother spending time doing this, it's the calc all the way for me http://www.rapidtables.com/calc/light/how-lux-to-lumen.htm}.

__Measuring PAR__
AS Nam correctly pointed out when measuring the light from an LED you will need to use a PAR Meter.

PAR Meters are not cheap , Apogee's Quantum PAR Meters start at around £240 / $360 which is out of a lot of peoples price range.

Here is a link to make a cheap DIY PAR meter from a cheap light meter -

https://www.autoflower.net/forums/f28/cheapest-par-meter-diy-40206.html#post770348