Solarmeter® Model 9.4G Blue Light GrowMeter - Solarlight

Solarmeter® Model 9.4G Blue Light GrowMeter

Model 9.4G Blue Light GrowMeter is used to monitor blue light intensity necessary to produce strong, healthy stems and leaves.




    • Compact, Handheld, and Durable
    • Simple Single-Button Operation
    • NIST Traceable Accuracy
    • LCD Display
    • Made In USA


  • Monitors Blue Light Intensity to Produce Strong, Healthy Stems and Leaves
  • Measuring Photosynthetic Action Spectrum Blue Band
  • Measuring Outdoor Blue Light

Sensor/Detector:GaP Photodiode packaged in hermetically sealed UV glass window cap. Filter used to narrow response as shown on the spectral response graph.

Operation:To operate your Solarmeter, aim the sensor window located on the top panel of the meter directly at a source. Press and hold the push-button switch on the face of the meter. For best results take note of the distance the reading was taken from the source in order to ensure repeatable results. Battery operation voltage is viable from 9V down to 6.5V. Below 6.5V, the numbers on the LCD display will begin to dim, indicating the need for battery replacement. Under typical service load, a standard 9V battery will last approximately 2 years.

Proper Usage of Solarmeter® Ultraviolet Radiometer

  • Wear actinic eye protection when checking blue lamps.
  • Allow lamps to warm-up prior to taking readings (at least 5 min).
  • Hold meter integral sensor close to source to measure individual lamp or LED intensity. Hold sensor at working distance from source for effective intensity.
  • When checking aging of lamps, keep measuring distance and locations constant.
  • Lamps should be replaced when output drops to about 70% of their original (new) readings.
  • If unsure of what new values were, replace a lamp with new one and compare old one.
  • Do not subject the meter to extremes in temperature, humidity, shock or dust.
  • Use a dry, soft cloth to clean the intrument. Keep sensor free of oil, dirt, etc.


0-199.9 mW/cm²

98% at 450 nm

422-499 nm

0.1 mW/cm²

3.0 Readings/Sec

3.5 Digit LCD

0.4 (in) / 10.2 (mm) high

32°F to 100°F / 0°C to 37.8°C

5% to 100% RH



4.2L x 2.4W x 0.9D (in) / 106.7L x 61W x 22.9D (mm)

4.5 oz / 128 (g) Including Battery

9-Volt DC Battery

UV Glass


GaP Photodiode with filter

CE Mark


Solarmeter® Model 9.4G Blue Light GrowMeter


SOLAR LIGHT COMPANY warrants that the equipment has been carefully tested, inspected and left the Factory in proper working condition, free of visible defects.  SOLAR LIGHT COMPANY warrants the equipment to be free from defects in material and workmanship, under normal use and operation, for a period of one (1) year after the date of initial operation, or demonstration; or eighteen (18) months from the date of shipment from the Factory; or whichever occurs first. The warranty is limited to the free replacement of all-defective parts and free labor during the first year of warranty.  Defective parts replaced under this warranty shall become the property of SOLAR LIGHT COMPANY. The above stated Warranty is subject to the following conditions: Equipment being installed within the United States of America, Canada, or sold by authorized SOLAR LIGHT COMPANY representatives or their agents outside the continental United States. The equipment being installed is operated and maintained in accordance with SOLAR LIGHT COMPANY’s operating instructions, maintenance instructions and specifications. Utilization of only SOLAR LIGHT COMPANY’s authorized parts and components.  The utilization of a duly authorized representative for all work performed on SOLAR LIGHT COMPANY equipment during the warranty period.  Any variation(s) to the above warranty must be in writing and mutually acceptable by SOLAR LIGHT COMPANY and the customer. The warranty shall not apply to damages resulting from errors in installation, nor shall it apply to any equipment, which has been subject to damages, alterations or misuse by the purchaser.  Parts of the equipment, which would be generally considered as expendable service items during normal use, such as fuses, lamps, detector shields, etc., are not covered under the warranty. THERE ARE NO WARRANTIES, WHICH EXTEND BEYOND THIS DESCRIPTION, AND EXPRESSLY NO IMPLIED WARRANTY OR MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SOLAR LIGHT COMPANY BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES OR ANTICIPATED LOSS OF PROFITS SUFFERED BY THE PURCHASER. Extended Warranty Plans are also available.