[[File:RH Circuit.jpg|none|thumb|Relative Humidity Circuit section]]
<br><br>== Disassembly ==<br This is a minimally-destructive disassembly method that will allow the payload to be held back together with about two feet of duct tape if you wish to reuse the payload for another weather balloon flight. # Cut the zip tie holding the plastic strap to the balloon/parachute tether rope. # Examine rope, parachute and parachute rigging lines for viability. Neatly organize the flight rigging if usable. Discard if not viable for reuse. # Peel open the battery/power cover from the bottom of the radiosonde and ensure that all 3 connectors are loose and not connected to one another.# Remove the plastic pins from either side of the radiosonde. # Peel away the paper wrapper starting with the corner near the external sensors# Tear the plastic strap off. It's held on mostly with a few staples into the styrofoam# Using a sharp utility razor, cut the bottom half of the shell off, carefully. The styrofoam is about 0.6 inch (15mm) thick on both the sides and bottom, so making a long cut all the way around the sides of the radiosonde, about 0.75" from the bottom edge, and not much deeper than 0.6" is recommended. You can use the exit of the weather sensors as a guide. DO NOT fully separate the radiosonde styrofoam shell yet.# Cut the tape holding the antenna into its dipole shape. Completely remove the tape and straighten the antenna wires.# Peel open the battery terminal access panel on the bottom again. Using a pair of tweezers, remove the small styrofoam block keeping the power wires restrained.# Push the battery wires through the hole as you peel apart the styrofoam shell. # The shell is glued together from the factory. Some of this glue will hold wires to the styrofoam shell. Carefully peel the sensor wires away from the foam and carefully pull the antenna wire (straightened in step 8) through the hole in the bottom of the shell.# The board should be completely separated from the two styrofoam shell halves. Set aside shell, plastic strap, plastic pins and paper wrap for possible re-use later. # Remove (3) Lithium CR-123A cells from the battery holders and discard of them safely. == Reassembly == # Place fresh lithium CR-123A cells into the battery holders. Use of rechargeable is not recommended for high-altitude flight.# Pass antenna wire through bottom part of shell. # Pass all 3 power wires through the bottom part of shell and into the power lead compartment.# Replace small styrofoam brick to hold power wires into the compartment. Do not connect any power wires together yet.# Route the antenna flat against the bottom of the shell and place duct tape over the hole.# Place upper half of shell onto lower half of shell# Using about 20 inches of Duct tape, close the edge of the radiosonde shell, ensuring that the weather sensors are able to exit the side of the shell where they originally did.# Using a small piece of tape, close the area between the weather sensor wires. You may wish to use additional tape to keep the shell closed effectively.# Place the plastic strap around the radiosonde as originally equipped. You can likely push the staples back into the styrofoam if they're left intact.# Optionally, re-attach the paper wrapper to the payload, or feel free to attach your own wrapper or identification.# Replace the plastic pins that hold the plastic strap to the radiosonde payload. You will need to push these pins through the duct tape applied in step 7.# Attach radiosonde strap to flight rigging (rope/>parachute/balloon or your choice of drone, kite, etc)# Remember to connect the red and white wires, and do a pre-flight telemetry verification immediately before launch. == Powering the radiosonde in the lab ==The OEM battery bank consists of three (3) CR-123A cells in series at 3.0VDC each, for a total of 9VDC. These cells are relatively expensive and only power the unit for 6-7 hours at a time. Internal battery power is enabled by connecting the white and red power wires together inside the compartment on the bottom of the radiosonde. The unit can be powered on the bench by providing 9VDC to the red power wire and connecting the black wire to power supply ground. Do not exceed 10VDC. Lithium-Ion rechargeable RCR-123A cells can also be used for testing. These cells will not likely last the duration of a high-altitude balloon flight due to both limited power capacity and cold temperatures at altitude.
==Connectors==