SENSOR MOUNTING ARM The Sensor Mounting Arm provides an ideal mounting location for all of your Davis weather station sensors. This manual is designed to take you through the process required to assemble and mount the Sensor Mounting Arm. Please take the time to read through this manual before beginning. C OMPONENTS The Sensor Mounting Arm includes the following components. Please make sure you have all listed components before continuing. ✦ Sensor Arm ✦ Mounting Bracket ✦ 16.
n. Two 1/2” U-Bolts (for anemometer arm) o. Two 1/2” Saddles p. Two 1-1/2” U-Bolts (for pipe with outside diameter between 1” and 1-1/4” (25 mm and 31 mm) q. Two 2-1/4” U-Bolts (for pipe with outside diameter between 1-1/2” and 2-3/8” (38 mm and 60 mm) r. Two 2-1/4” Saddles s. Three #8-32 x 3/4” (19 mm) Screws t. Two #8-32 x 2 -1/2” (64 mm) Screws T OOLS AND M ATERIALS N EEDED In addition to the components listed above, you will need some of the following tools and materials.
The Sensor Arm The illustration below shows the sensor arm and indicates which holes are used by the various sensors, brackets, and accessories. SENSOR ARM HOLE ASSIGNMENTS Typical Sensor Mounting Arm Installation The illustration below shows a typical Sensor Mounting Arm installation with all possible sensors attached to the sensor arm.
A TTACHING THE M OUNTING B RACKET In order to attach the mounting bracket to the sensor arm, you will need the sensor arm, mounting bracket, two #8-32 x 2-1/2” screws, four #8 flat washers, two #8 split lock washers, and two #8-32 hex nuts. 1. Place one #8 flat washer over the end of each of the #8-32 x 2-1/2” screws. 2. Position the mounting bracket so the holes in the mounting bracket line up with the appropriate holes on the sensor arm. 3.
A TTACHING THE A NEMOMETER You may mount the anemometer on either side of the sensor arm. The preferred mounting location for the anemometer is on the end closest to the mounting bracket. However, if you have an anemometer with a straight arm and a Rain Collector attached to the Sensor Mounting Arm, the Rain Collector might create obstruction problems which result in inaccurate wind speed and direction readings.
Attaching the Anemometer Below the Sensor Arm (Preferred) To attach the anemometer below the sensor arm, you will need the anemometer, sensor arm, two 1/2” U-bolts, two 1/2” saddles, four 1/4” flat washers, four 1/4” split lock washers, four 1/4” hex nuts, one cable clamp, one #8-32 x 3/4” screw, one #8 flat washer, and one #8-32 hex nut. ANEMOMETER ATTACHED BELOW SENSOR ARM 1. If necessary, disconnect the anemometer from your weather station.
6. Slide the ends of the U-bolts into the appropriate holes at the end of the sensor arm nearest the mounting bracket. SLIDE U-BOLTS INTO HOLES 7. Secure the U-bolts and anemometer arm in place using a 1/4” flat washer, 1/4” split lock washer and 1/4” hex nut on each of the U-bolt ends. Tighten the hex nuts with your hand so the arm is gently held in place. Do not tighten fully until instructed to do so later on.
. Slide the anemometer arm backwards/forwards until the end of the anemometer arm extends just 1/2” (13 mm) past the second U-bolt/saddle. POSITION ANEMOMETER ARM 9. Once the anemometer arm is correctly positioned, tighten the hex nuts. In order to keep the anemometer arm steady in high winds, tighten the hex nuts until you notice the anemometer arm just begin to buckle underneath the U-Bolt. 10. Place a cable clamp around the anemometer cable. 11.
Attaching the Anemometer Above the Radiation Shield To attach the anemometer above the sensor arm, you will need the anemometer, sensor arm, two 1/2” U-bolts, two 1/2” saddles, four 1/4” flat washers, four 1/4” split lock washers, four 1/4” hex nuts, one cable clamp, one #8-32 x 3/4” screw, one #8 flat washer, and one #8-32 hex nut. ANEMOMETER ATTACHED ABOVE SENSOR ARM 1. If necessary, remove the Radiation Shield from the sensor arm.
7. Position the U-bolts/saddles on top of the sensor arm on the side farthest from the mounting bracket so the ends of the U-bolts drop into the appropriate holes. SLIDE U-BOLTS INTO HOLES 8. While holding the U-bolts in place, turn the sensor arm over so the protruding ends of the U-bolts are visible. 9. Secure the U-bolts and anemometer arm in place using a 1/4” flat washer, 1/4” split lock washer and 1/4” hex nut on each of the ends of the U-bolts.
10. Slide the anemometer arm backwards/forwards until the end of the anemometer arm extends just 1/2” past the second U-bolt/saddle. POSITION ANEMOMETER ARM 11. Once the anemometer arm is correctly positioned, tighten the hex nuts. In order to keep the anemometer arm steady in high winds, tighten the hex nuts until you notice the anemometer arm just begin to buckle underneath the U-Bolt. 12. Place a cable clamp around the anemometer cable. 13.
15. Secure the cable clamp and cable in place using an #8 flat washer and an #8-32 hex nut. Tighten the hex nut until the cable is held snugly within the cable clamp. Note: When you attach (or reattach) the Radiation Shield beneath the anemometer, you will find that one of the Radiation Shield’s mounting screws is between the U-bolts/saddle, and will be difficult to access. You will need a nut driver or socket wrench in order to tighten this nut.
Mounting the Sensor Mounting Arm on a Small Pipe Follow the instructions below to mount the Sensor Mounting Arm on a pipe with an outside diameter between 1” and 1-1/4” (25 mm and 31 mm). To attach the sensor arm to a small pipe, you will need the sensor arm assembly (with mounting bracket and sensors attached), two 1-1/2” U-bolts, four 1/4” flat washers, four 1/4” lock washers, and four 1/4” hex nuts. Note: When mounting on a small pipe, the Sensor Mounting Arm must be mounted at the top of the pipe. 1.
Mounting the Sensor Mounting Arm on a Large Pipe Follow the instructions below to mount the Sensor Mounting Arm on a pipe with an outside diameter between 1-1/2” and 2-3/8” (38 mm and 60 mm). To attach to a large pipe, you will need the sensor arm assembly (with mounting bracket and sensors attached), two 2-1/4” U-bolts, two 2-1/4” saddles, four 5/ 16” flat washers, four 5/16” lock washers, and four 5/16” hex nuts. 1. Wrap one of the 2-1/4” U-bolts around the pipe and hold it in place. 2.
G ROUNDING THE S ENSOR M OUNTING A RM We strongly recommend that you ground the sensor arm. You will need the 16.5’ (5 m) ground wire, one #8 split lock washer, and one #8-32 hex nut. 1. Slip the ring at the end of the 16.5’ (5 m) ground wire over the lug on the underside of the sensor arm. 2. Secure the ground wire to the lug using a #8 split lock washer and a #8-32 hex nut. SECURE GROUND WIRE TO SENSOR ARM 3.
M AINTAINING THE S ENSOR M OUNTING A RM You should check the tightness of the various screws and U-bolts periodically. Pay particular attention to the U-bolts holding the anemometer arm in place. T ECHNICAL S UPPORT Before calling Technical Support (1-510-732-7814), carefully check this instruction manual for the answer to your question. Product Number: 7702 Davis Instruments Part Number: 7395-091 Sensor Mounting Arm Rev.
