Demountable Electrode Contact Pellet for Photoionisation Detector
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing demountable electrode contact assemblies for photoionisation detectors face challenges with maintaining good electrical contact due to manufacturing tolerances, corrosion, and debris accumulation, leading to reduced sensitivity and increased costs.
Innovation Solution
A demountable electrode contact assembly with a base and closure system where electrode contacts are deformed into a common plane upon assembly, allowing fixed terminal pins to engage and deform the contacts for scraping engagement, enhancing ohmic contact and alignment while minimizing environmental effects and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If spring-loaded retractable pins are used for electrical contact, then ease of assembly is improved, but reliability deteriorates due to loss of spring loading and corrosion
Solution Approach 1:
The assembly is divided into a disposable electrode pellet and a reusable detector body. The electrode contacts are integrated into the pellet as simple protrusions rather than complex spring-loaded mechanisms, allowing the pellet to be easily replaced while maintaining reliable electrical contact through the simple protrusion-to-hole interface.
Solution Approach 2:
The electrode pellet is designed as a disposable component that is replaced periodically. This eliminates the need for maintenance of complex electrical contact mechanisms, as the entire electrode assembly including contacts is discarded and replaced, ensuring consistently reliable contact without degradation over time.
2Manufacturing precision
If pins inserted into metal holes are used, then manufacturing precision is improved, but reliability worsens due to failure after multiple engagement and removal
Solution Approach 1:
The electrical contact interface is segmented between the disposable pellet (with protrusion contacts) and the reusable detector body (with hole receptacles). This allows the precision-machined holes to remain in the durable detector body, while the pellet with simpler protrusion contacts is replaced, combining manufacturing precision with durability.
Solution Approach 2:
The electrode contacts are pre-formed as protrusions during pellet manufacturing, eliminating the need for field assembly or adjustment. The pellet is pre-assembled with electrodes positioned to engage the detector body holes, ensuring consistent alignment and eliminating wear from repeated engagement and removal.
3Ease of manufacture
If electrode contacts are in spaced parallel planes, then ease of manufacture is improved, but manufacturing precision worsens due to alignment tolerances
Solution Approach 1:
The electrode contacts are designed with flexibility to allow deformation during assembly. The contacts can be deformed from their initial spaced parallel planes configuration into a common plane through mechanical engagement with the closure member, accommodating manufacturing tolerances while achieving the required coplanarity for reliable electrical contact.
Solution Approach 2:
The physical state of the electrode contacts changes during assembly through deformation. The contacts transition from a rigid spaced parallel planes configuration to a deformed state where they lie in a common plane, allowing the system to accommodate manufacturing variations and achieve the required precision through controlled deformation rather than requiring precision in the initial manufacturing.
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 provides reliable, cost-effective, and durable electrical connections that maintain sensitivity by aligning and cleaning the contact surfaces, reducing the need for precise alignment and minimizing environmental impact through the use of a simple, two-part design.
Implementation Method 1
a closure for the base having at least one member engaging a corresponding electrode contact, wherein, in an assembled condition of the electrode contact assembly, with the closure separate from the base and the at least one closure member disengaged from its respective electrode contact, the contacts lie in respective spaced parallel planes and wherein, in the assembled condition of the electrode contact assembly with the at least one closure member engaging its respective electrode contact, at least one of the contacts is co-planar with another of the contacts
Implementation Method 2
each electrode contact overlies a corresponding hole in the base through which respective fixed terminal pins are receivable from the exterior of the electrode contact assembly to provide ohmic contacts therebetween
Implementation Method 3
The terminal pins, when received through their respective holes in the base, deform their corresponding electrode contacts in a direction generally opposite to that of the initial deformation of the contacts when the capsule is assembled. The scraping action of the rounded terminal pins upon the flat surfaces of the electrode contacts removes oxide and other debris between the respective contact/terminal surfaces
Data Source
Figure 1~2
Figure 3
Figure 4~8
AI summary
A demountable pellet is disclosed for use as an electrode contact assembly. The pellet comprises a base 1 upon which is mounted a plurality of electrodes 18,19,20 arranged in respective spaced parallel planes and having respective contacts 23,24,25 protruding from them. A closure 2 for the base 1 has a member 11,12,13 engaging at least one of the electrode contacts. In an unassembled condition of the pellet, with the closure 2 separate from the base 1 and each closure member disengaged from its respective electrode contact, the contacts 23,24,25 lie in respective spaced parallel planes. In the assembled condition of the pellet with each closure member engaging its respective electrode contact, at least one of the contacts 23,24,25 lies in a plane other than that in which it lay in the unassembled condition of the pellet.