Section 7
LN2 Level Monitor
Troubleshooting and Parts List
Cryogenic Storage Vessel
7-1
Thermo Scientific
Problem
Cause
Solution
Level monitor alarm sounds intermittently.
Unit measuring liquid level incorrectly.
Ice or frost buildup on the transducer.
Remove level monitor from vessel and place in
room for approximately two hours, or until no ice
is visible on the transducer or tube. Make sure lid
is standing upright on the cork to allow moisture
to drain out of level monitor. Wipe any moisture
away from the inside of the tube and face of the
transducer with a clean soft cloth. Place level
monitor back on unit. (Remember to press “Reset”
button.)
Level monitor measuring “Full” after
removing samples and replacing lid.
Fog in top part (neck area) of cryogenic vessel.
The density of the fog that is formed after remov-
ing the lid and accessing samples is dependent
on the humidity of the room where the cryovessel
is located. The fog dissipates after about fifteen
minutes and at this time, the level monitor will
take an accurate reading of the liquid nitrogen
level.
Ordering Procedures
Refer to the Specification Plate for the complete model number, serial
number, and series number when requesting service, replacement parts or
in any correspondence concerning this unit.
All parts listed herein may be ordered from the Thermo Scientific dealer
from whom you purchased this unit or can be obtained promptly from the
factory. When service or replacement parts are needed, check first with
your dealer. If the dealer cannot process your request, then contact
Technical Services.
Prior to returning any materials, please contact our Technical Services
Department for a “Return Materials Authorization” number (RMA).
Material returned without an RMA number will be refused.
