15
Principles of Operation
The innovative LIQUID NITROGEN LEVEL MONITOR from
Thermo Scientific utilizes ultrasonic sound waves to sense
the level of liquid nitrogen inside a or LOCATOR Plus cryo-
genic storage vessel. A microprocessor control provides
continuous indication of the liquid nitrogen level inside the
LOCATOR or LOCATOR Plus. Audible and visual alarms
also provide an early warning of low level conditions.
ULTRASONIC sound waves sense the level of liquid nitro-
gen inside the LOCATOR or LOCATOR Plus vessel.
By using ultrasonic sound waves to sense the level of liq-
uid nitrogen, no physical probe is required to sense the
level of liquid nitrogen. Conventional devices use probes
which must be in physical contact with the liquid. This
physical contact increases liquid nitrogen consumption.
There is NO increase in liquid nitrogen consumption by
using the Thermo Scientific LEVEL MONITOR.
Microprocessor Functions
5 segment LED indication of the liquid nitrogen level
The LED display is graduated in 5 segments; Full, 3/4, 1/2,
1/4 and Empty, similar to a fuel gauge on an automobile.
The bright orange LED display provides quick and reliable
visual indication of the level of liquid nitrogen inside the
LOCATOR or LOCATOR Plus vessel.
A
CCESSORY
L
IQUID
N
ITROGEN
L
EVEL
M
ONITOR
O
PERATION
1
2
3
6
5
4
Load
J3-2
J3-1
U4
V
Load Voltage
(DC)
L
Remote Alarm Connections Schematic
The position of J4 and J6 indicate
whether the relay is normally open
or normally closed.
