The observatory is equiped with the 6-NM64 neutron monitor sensitive to cosmic rays penetrating the Earth's atmosphere with energies from about 0.5-20 GeV. Neutron monitors are ground based cosmic ray detectors. More information about these devices can be found on the international neutron monitor (NEST) database website. Galactic cosmic rays (GCRs) born in the remnants of stellar explosions and active galaxies come from the outer heliosphere toward the Sun. GCRs create a background of high-energy protons and Helium nuclei measured by neutron monitors most of the time. When the Sun is active, it ejects accelerated particles to the interplanetary space. Their population with energies up to the MeV range is called solar energetic particles (SEPs), and the most energetic particles with energies above the MeV range are called solar cosmic rays (SCRs). Increases in the SCR flux are detected by neutron monitors as so-called "ground level enhancements" (GLEs). The GCR intensity and the GCR intensity anticorrelate varying over the solar cycle. Cosmic rays, as all energetic particles, are sensitive to the magnetic field, therefore their transpot and intensity variations depend on the properties of the solar wind (the medium through which they propagate).

The Mount Hermon neutron monitor measures cosmic rays since 1998, when a joint experiment has been established in collaboration between the Italian Institute for Interplanetary Space Physics IFSI/CNR, University "Roma Tre" and Tel Aviv University (Israel). The observatory measures the total counting rate, and multiplicities from 1 to 8 are recorded every minute. There are also measurements of the barometric pressure, the temperature, the internal relative humidity, the wind velocity and its direction, and the low and high voltages values. The laboratory is protected by a Faraday grid, protecting the sensitive instruments from the lightning activity.

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The data for 1998-2009 are available at the NEST website (select the "ESOI" observatory) and the data from 2009 to 2018 can be found on this webpage (see the data description here). Any questions regarding the experiment and data can be sent to Dr. Lev Pustilnik.