LSM Light Sensor Meter for PAR Sensors

The LSM Light Sensor Meter is designed to continuously monitor photosynthetically active radiation (PAR).

The LSM Light Sensor Meter is most commonly used to monitor plant canopy light interception. A point PAR sensor, such as Decagon’s QSO-S or Apogee’s SQ-110, is installed above the plant canopy to measure ambient light conditions. Within and beneath the canopy, one or more LINPAR linear PAR sensors can be installed. This way, the fraction of absorbed radiation or leaf area index can be calculated.

The LSM Light Sensor Meter has an internal lithium ion battery which is charged by an external solar panel. The unit is IP65 rated and can tolerate all weather conditions encountered in the field. All data is logged to an internal 4GB MicroSD card which can be downloaded as a csv file. Data can also be downloaded via the internet if used in combination with the MCC2G Data to Web module.

Instrument Logging

Analogue Channels 10 single ended
Resolution 0.00001V—24-Bit
Accuracy 0.001V
Minimum Logging Interval 1 second
Delayed Start Suspend Logging, Customised Intervals
Sampling Frequency 10Hz


Communications USB, Wireless Radio Frequency 2.4 GHz
Data Storage MicroSD Card, SD, SDHC & SDXC Compatible (FAT32 format)
Software Compatibility Windows 7, 8, 8.1 & 10; Mac.
Data Compatibility FAT32 compatible for direct exchange of SD card with any Windows PC
Data File Format Comma Separated Values (CSV) for compatibility with all software programs
Memory Capacity Up to 16GB, 4GB MicroSD card included.

Operating Conditions

Temperature Range -40°C to +80°C
R/H Range 0-100%
Upgradable User Upgradeable firmware using USB boot strap loader function


Internal Battery Specifications
960mAh Lithium Polymer, 4.20 Volts fully charged
External Power Requirements
Bus Power 8-30 Volts DC, non-polarised, current draw is 190mA maximum at 17 volts per logger
USB Power 5 Volts DC
Internal Charge Rate
Bus Power 60mA – 200mA Variable internal charge rate, maximum charge rate of 200mA active when the external voltage rises above 16 Volts DC
USB Power 100mA fixed charge rate
Internal Power Management
Fully Charged Battery 4.20 Volts
Low Power Mode 3.60 Volts – Instrument ceases to take measurements
Discharged Battery 2.90 Volts – Instrument automatically switches off at and below this voltage when no external power connected.
Battery Life varies
Example A: With a recommended solar panel and/or recommended power source connected, operation can be continuous.
Example B: Power consumption is dependent on number and type of sensors connected, frequency of measurement and measurement duration