Liquid Nitrogen Level Monitor (Model 729A)
- Prevents loss of data
- Avoids thermal cycling of older HPGe detectors
- For HPGe coaxial, LEPS, and Si(Li) systems
- Sounds alarm when liquid nitrogen level is low
- Available with a variety of thermistor probes
- Battery backup
- Totally fail-safe
The ORTEC Model 729A Liquid Nitrogen Level Monitor is a single-width
module (NIM-standard) designed to serve as an accessory on Germanium (HPGe) coaxial (GEM and GMX),
LEPS, Si(Li), and old Ge(Li) detectors in the field.There are two uses for the 729A: (1) for customers whose applications
will not tolerate detector warmup, (e.g., unacceptable loss of experimental data); (2)
guarding against thermal cycling older HPGe detectors.
When used with the appropriate probe, the monitor will sound an alarm
long before the detector can warm up as a result of loss of liquid nitrogen in the dewar.
The level of liquid nitrogen is sensed by a thermistor probe in the dewar. When the liquid
nitrogen falls below a safe level (approximately 1/4 of the dewar capacity), an alarm
sounds and a red light on the front panel of the control module flashes a warning.
The module is totally fail-safe with a battery backup in case of power
failure and an audible, flashing alarm that sounds if: (1) bin power is shut off, (2) the
sensor is broken, (3) the sensor is disconnected, or (4) an attempt is made to remove the
module from the bin.
Impedance considerations do not permit using the detector’s
internal, high-voltage shutdown and the Model 729A together. A 3.66 m (12 ft) BNC coaxial
cable for connecting the probe to the Model 729A is included.ORDERING INFORMATION
|
Model |
Description |
|
729A |
Liquid Nitrogen Level Monitor
for all Ge and Si(Li) detectors (does not include probe) |
|
LNP-7D |
Probe for use with 729A; fits
standard 7.5-liter and 13-liter bucket (SL, PS) type dewars |
|
LNP-30B |
Probe for use with 729A; fits
30-liter bucket type dewar |
|
LNP-30D-2 |
Probe for use with 729A; used
with dipstick cryostat CFG-PH-2 only |
|
LNP-30D-3 |
Probe for use with 729A; used
with all dipstick cryostats except CFG-PH-2 |
|
