Innoquest introduces the SpotOn Quantum PAR Light Meter

The light meter provides an inexpensive solution for growers to measure LED and other sources of light.


Innoquest has introduced a versatile quantum PAR light meter that aims to appeal to large and small greenhouse growers, as well as hobbyists using artificial lighting to grow plants indoors. 

The SpotOn Quantum PAR Light Meter is a scientifically accurate instrument that takes readings from any source, including LEDs.

Until now, growers have had to spend up to $1,500 for a PAR light meter. The SpotOn Quantum PAR Light Meter will retail at $295, making it affordable to hobby and small growers, large growers looking to purchase multiple units, researchers and anyone relying on artificial light to grow plants.  

“This tool was invented to allow growers to obtain fast readings in three different modes of operation,” said Bill Hughes, President of Innoquest, Inc. “Before this tool, inexpensive light meters weren’t compatible with LED lighting. Growers had to use expensive research quality light meters.” 

Why PAR readings are important

Photosynthetic Active Radiation (PAR) is the best measure of the quantity of photosynthetic light that is reaching the surface of the plant and is measured in micromoles per meter squared per second. Like monitoring the pH of the soil, taking regular PAR readings of a light source will help growers make decisions regarding the type of lights they are using, when bulbs need to be replaced, how close to suspend light fixtures from plants and deciding if it is time to replace a greenhouse covering. 

Three modes of operation 

This compact, water-resistant light meter features three forms of operation that provides growers the information they’ll need to monitor and make any adjustments to their lighting:  

  • Instantaneous PAR Light Readings
  • Scan function to quickly calculate Coverage Area Average
  • Daily Light Integral (DLI) display (measures the cumulative total amount of PAR that reaches your plants during a 24-hour photoperiod)

 How it works

  • The SpotOn Quantum PAR Light Meter takes PAR readings about once per second. The meter’s software automatically stabilizes readings from 50 or 60 Hz light sources. To obtain an average reading for a lighted area, you can press and hold the SCAN button and wave the meter throughout the area where you want to obtain the reading.
  • This meter takes a light reading every three minutes, even when display is off. The DLI is calculated for the past 24 hours and is updated every 15 minutes. The DLI value appears on the display when the power button is pressed.