Frequently Asked Questions

Frequently Asked Questions


  • PAR - PYR - SUPPORTING SENSORS Can PAR be estimated from total shortwave radiation?

    It is better to measure PAR and total shortwave radiation (PYR); however, PAR can be estimated from total shortwave radiation by using a physically based model.

  • PAR - PYR - SUPPORTING SENSORS How do I know when my PYR or PAR needs to be recalibrated?
    Use the Apogee Clear Sky calculator. The primary use of this calculator is to determine the need for recalibration of radiation sensors. It is most accurate when used near solar noon in the summer months.
  • PAR - PYR - SUPPORTING SENSORS How do I mount the leveling plate to the mounting bracket?
    You can find PAR/PYR installation instructions in the quick start guide and on page 9 of the manual. On the leveling plate, the outer screws (with threads in the plate) are for leveling, and the inner screws (no threads) are used to secure the leveling plate to the mounting bracket. First, securely install the mounting bracket to a post, considering the optimal position for collecting accurate solar radiation data. Orient the sensor cable as described in the quick start and manual.
    1.  Screw in the inner screws part of the way, to secure it to the mounting bracket.
    2.  Screw in the outer screws until the bubble level indicates the leveling plate is level.
    3.  Screw in the inner screws to completely secure the leveled leveling plate to the mounting bracket.
    4. Remove the green cap after installation is complete.

  • ATMOS 14 - SRS - IRT - ECT - PAR - PYR - ATMOS 22 - ATMOS 41 - PHYTOS 31 - ECRN-100 - ECRN-50 How do I assemble the anemometer mast?

    The anemometer mast is suitable to mount METER’s above-ground sensors: ATMOS 41, ATMOS 22, ATMOS 14, PAR, PYR, IRT, SRS, PHYTOS 31, ECRN-100, ECRN-50, and ECT. Additional brackets may be required for some products.

    Anemometer mast kit: 1 extendable mast (fiberglass), 1 guy ring, 1 guy rope (7.6 m nylon rope), 3 guy rope anchors, and 1 mast base with center peg and set screw.

    Mast diameter: 4.5 cm

    Mast adjustable length: 1.3 to 2.3 m

    Tools to bring to the field: measuring tape, long metal screwdriver, mallet, wrench, level, scissors, optional shovel, and lighter.

    Installation:  Position the mast base in the desired installation location, avoiding large rocks. Install the center peg using a mallet. Insert the mast into the base so that the center peg is inside the mast tube. With the mast in the base, turn the set screw so it is hand-tight against the mast. Then, gently turn the set screw with a wrench. Do not over tighten or the fiberglass pole will break. Put the guy ring over the extendable mast. Cut the guy rope into thirds (approximately 2.5 m each) and burn the ends with a lighter to prevent fraying. Position the rope anchors equidistant apart to be about 1 meter away from the mast. Screw the anchors into the soil at the same angle as the guy rope using a long metal screwdriver as a make-shift turning handle. Attach the guy rope to the guy ring in 3 equidistant holes (show below) using knots. Then knot each guy rope in the corresponding anchor. Pull the rope very tight and ensure the mast is level and straight.

    Once the mast is secure, move the adjustable lever up to release the extendable mast. Move the lever down to secure the mast to the correct height. Install instruments following the sensor quick start guides and manuals.

    Limitations: Rocky soils, long-term monitoring sites, locations with high animal traffic. The SRS extension arm may be too heavy for the fiberglass mast.