Campbell Manufacturing LIQUID LEVEL DB1 Manual De Usuario

•  Inspect submerged bubbler tubes for sediment or other debris.  Remove 

debris and clean tubes as required. 

•  Replace submerged bubbler tubes if cracked or damaged. 

•  Replace nitrogen bottle every 2 to 3 months depending on bubble rate. 

•  Inspect valves for leaks every 2 to 3 months and tighten or replace as 

required (refer to discussion on valves below). 

•  Inspect fittings for leaks every 2 to 3 months and replace as required. 

•  Inspect desiccant indicator cards and replace desiccant when card begins 

to change color from blue to pink. 

Over time, the knurled ring on the solenoid valve may become loose due to 
expansion and contraction.  This problem is corrected by simply turning the 
knurled ring clockwise until finger tight.  Two other possible problems are 
contamination or complete failure.  In the case of contamination, the valve 
would not open or close properly, resulting in deviant pressure measurements. 

The solenoid valve can be disassembled to inspect for possible contamination 
by removing the top half of the valve.  Turn the knurled ring counter-clockwise 
until the threads are disengaged and pull upward on the top half of the valve 
assembly.  There are two parts inside the valve, a very thin washer and a spring 
plate.  Be aware, the washer may stick to the top half of the valve during 
disassembly.  Clean any contamination from the valve or spring plate.  Inspect 
the rubber seal on the spring plate for cracks or damage (replace valve if seal is 
damaged).  Reassemble by placing the spring plate in the base (rubber seal 
down) followed by the washer.  Re-insert the top half and tighten the knurled 
ring finger tight.  If the spring plate is damaged the valve will need to be 
replaced (see Section 7). 

The seals in the fittings may eventually become dry and cracked, resulting in 
leaks and inaccurate pressure measurements.  If this occurs, the fittings will 
need to be removed and replaced (order P/N 7397:  1/4 inch tubing x 1/8 npt 
90 degree elbow and P/N 5199:  thread sealant).  Apply a small amount of 
thread sealant to the threads on the fitting and thread fitting in finger tight.  
Using a torque wrench, tighten fitting between 5 to 6.5 ft-lbs. 

The needle valves should not require any maintenance. The seals should 
perform properly for several years.  A light film of vacuum grease was applied 
to the seals and should prevent them from drying and cracking.  If a valve is 
damaged simply remove and replace the valve order P/N 7558 or return the 
DB1 to Campbell Scientific for repair.