Liquid Nitrogen Sensor Mount With Foam Buffer for Low-Frequency Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Low frequency noise caused by vibrations from bubbles during liquid nitrogen evaporation affects measurement accuracy in SQUID sensor devices used in underground resource exploration and geomagnetic observation, and existing solutions either fail to adequately absorb vibrations or complicate sensor replacement and nitrogen refilling.
Innovation Solution
A liquid nitrogen cooling sensor device container with a sensor fixing member and a fixing buffer member, such as melamine foam or PVA sponge, that absorbs vibrations while allowing easy insertion and removal of the probe, ensuring stable measurements over long periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the sensor is directly immersed in liquid nitrogen using a rod-shaped probe rod, then the sensor can be disposed close to the container bottom surface for effective liquid nitrogen utilization, but the sensor is directly affected by vibration caused by bubbles generated as the liquid nitrogen evaporates
Solution Approach 1:
A buffer member (made of foam material such as polyethylene foam or polyurethane foam) is introduced as an intermediary between the probe rod and the liquid nitrogen. This buffer member absorbs vibrations caused by bubble generation during evaporation, while still allowing the probe rod to be immersed in liquid nitrogen for effective cooling. The buffer member transmits only minimal vibration to the sensor, thus resolving the contradiction between cooling efficiency and measurement accuracy.
2Object-generated harmful factors
If a rough surface member is provided on the inner bottom surface of the container to prevent large bubbles from being generated, then large bubble generation is controlled, but relatively small bubbles are still generated and low frequency noise due to sensor vibration remains
Solution Approach 1:
The buffer member made of foam material serves as an intermediary that absorbs vibrations from both large and small bubbles generated during liquid nitrogen evaporation. Unlike the rough surface member that only addresses large bubbles, the foam buffer material's cellular structure effectively dampens vibrations from bubbles of all sizes, eliminating low frequency noise while allowing continuous evaporation to proceed.
3Stability of the object's composition
If a concaved recess is formed in the bottom portion of the container with a rod fitted in it, then the sensor is fixed and stabilized, but the rod cannot be freely inserted and pulled out while liquid nitrogen is contained, making sensor replacement and liquid nitrogen refilling difficult
Solution Approach 1:
The buffer member made of foam material acts as an intermediary that provides flexible fixation. The foam's compressible nature allows the probe rod to be easily inserted and removed, while simultaneously providing enough resistance to stabilize the sensor during measurement. This resolves the contradiction between sensor stability and ease of operation for replacement and refilling.
4Duration of action of stationary object
If the sensor is attached to the distal end of a long probe rod for long period liquid nitrogen cooling, then the sensor can be cooled for extended periods, but even slight vibration vibrates the probe rod to produce measurement noise
Solution Approach 1:
The buffer member made of foam material is positioned between the probe rod and the sensor to absorb vibrations along the long probe rod. The foam's damping characteristics reduce the transmission of vibrations from the probe rod to the sensor, enabling stable measurements during long-duration cooling operations without the measurement noise that would otherwise be produced by probe rod vibration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces low frequency noise and allows for easy maintenance by absorbing vibrations, enabling stable and accurate measurements during prolonged liquid nitrogen cooling processes.
Implementation Method 1
The fixing buffer member exerts a buffering effect in the liquid nitrogen, absorbing the vibration of the probe caused by bubbles generated as the liquid nitrogen evaporates
Implementation Method 2
a sensor fixing member which has a distal end portion to which a sensor operating at a temperature of the liquid nitrogen is attached
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a liquid nitrogen cooling sensor device container and liquid nitrogen cooling sensor equipment, and effectively reduces low-frequency noise while maintaining the ease with which a probe can be inserted in and removed from liquid nitrogen. Said invention comprises: a liquid nitrogen containing insulating container that contains liquid nitrogen; a sensor fixing member which has a distal end portion to which a sensor operating at a temperature of the liquid nitrogen is attached; and a fixing buffer member which is for fixing the sensor fixing member to the liquid nitrogen containing insulating container, wherein the fixing buffer member exerts a buffering effect in the liquid nitrogen.