A multi-gas personal monitor warns users of hazardous gas present in their working environment. It has the capability to monitor up to five gases at a time with its four gas sensors, one being a dual sensor. We had the opportunity to design and engineer an entire suite of products relating to a multi-gas personal monitor, including the monitor itself, a single charger, an add-on pump, and a gang calibrator-charger.
The whole family of products is intrinsically safe, including the battery pack. We designed the products to meet IP65 ratings (e.g. water and dust tight) and also UL (Underwriters Lab) classification using sealed geometry and careful material selection. After completing and testing the designs we communicated our results to UL to certify compliance with the necessary standards. The hand-held monitor has custom-designed sealed ports and a sealed auditory system. Our mechanical engineers created detailed Solidworks models for efficient moldable parts, including some over-molded components, and integrated pushbuttons directly into the case. A lightpipe was designed for the charging status indicator LEDs to avoid light bleed, allowing for a clear bright light that is immediately visible from a distance. The gang calibrator-charger was carefully engineered to avoid any gas leaks and optimize manufacturing costs by combining all of its components into a single moldable part. All of the components in our electrical schematic drawings were systematically considered for intrinsic safety and other necessary ratings. Our electrical engineers worked closely with our mechanical engineers to design the numerous board layouts. The many boards across the product family had to be meticulously designed so as to fit within the physical constraints of the mechanical layout of the device. Since most of the mechanical components had been 3D printed the assessment of the design feasibility was made quick and easy. One of the biggest challenges of this project was meeting the complex requirements of a high-contrast, high-resolution, wide temperature range display that was still compliant with intrinsic safety requirements. We accomplished this feat by designing a custom display. Another successful accomplishment was our re-design of the manifold in the gang calibrator-charger. We were successfully able to reduce the number of tubes in the manifold from 30 all the way down to 8.