Mounting Monnit Coin-Cell Sensors in Solar Radiation Shields

Supplies needed:

Solar Radiation Shield—Unfortunately Monnit doesn’t sell any sun shields for their sensors.  It your sensor will be exposed to the sun it must be shielded to provide accurate readings.  This shield from Ambient Weather in Phoenix costs $7 and is the best solution I have found.  Order one for each sensor you need to shield.


Tape to keep insects out—I have found the best tape is Gorilla Tape.  It sticks well, is easy to tear and remove, and is available just about everywhere.  

Vinyl Coated Wire (20 inches per sensor)—The best wire is garden “training wire” but any non-rusting wire will do; Home Depot sells it in the garden department from Vigoro or get it from by searching for “gardener's training wire”.

Rope or cord to hang in shield in greenhouse--Just about any kind of cord will do to hang the shield over a truss or hoop in the greenhouse.  Be sure to use enough so you can adjust the height.

Conduit Clamp for post mount--Use this to easily mount the shield on a tomato stake or other post in the field.  At Home Depot, Lowes or electrical supply store get a #5 Conduit Hanger which is about 2 1/4 in in diameter.  



1. Use a paperclip or pointed instrument to insert the battery, plus side down, toward back, into the slot in the sensor body.  Be sure to push the battery ALL THE WAY IN.  Using just your finger to push it in will not be far enough.  If you get a negative reading is usually means the battery is not pushed all the way in.


2. Add tape to keep insects out.  Tear a piece of Gorilla tape 4 3/4 in long, and 1/4 in wide.  Fold one end over 1/4 inch to make a tab you can use to remove the tape to change the battery.  Make sure the tape covers the battery removal hole on one side and the battery insertion slot and cover sticker on the other.  DO NOT cover the actual sensor, the blue protrusion in the picture below.


3. Drill a hole a little larger than the vinyl coated wire in the top center of the shield.  If you have a extension or long bit it is easier to center the hole if you insert the drill bit from the bottom, inside rather than drilling from the top.

4. Cut a 20 inch piece of vinyl coated training wire.  With the sensor antenna pointing down, Insert 5 inches of it into a mounting hole from the FRONT of the sensor, then around back and into the other hole, then wrap it around itself as shown below.

5. Lay the wire next to the shield with the sensor antenna pointing down and out of the shield as shown below.  Make a small loop in the wire where it will be at the top inside of the shield when the wire is inserted into the shield.  When the wire and sensor are in the shield the loop will keep the antenna in the proper place outside of the shield.

6. Insert the wire into the shield from the bottom and make a loop at the top for hanging the shield as shown below:


7.  To hang in a greenhouse use a piece of rope or cord through the top loop to hang it on a truss or hoop.  BE SURE TO ALWAYS KEEP THE SENSOR ANTENNA VERTICAL.

8. To mount on a post in the field use a #5 conduit hanger (see above), remove the bolt and spread the hanger sides apart and press the shield into the hanger to fit snugly.  For extra security add a piece of wire the two sides of the hanger together as shown below  Use a screw through the hole in the hanger to attach it to a post.  ALWAYS KEEP THE SENSOR ANTENNA VERTICAL.