DUAL PLATFORM PRECISION SCALE

This project was commissioned by GSA as our MSc PDE Human Factors project. My team and I were tasked to evaluate, test, and re-design a Heston Blumenthal Dual Platform Precision Scale from a human factors standpoint. For the first six weeks we evaluated and researched as a team, while the following six weeks consisted of our personal re-designing and testing.

My personal re-design focuses on the cleaning, handling, and intuitive experience.

By increasing the length of the body to a Golden Ratio proportion compared to the width, more space was available to play with. On top, this extra space can be seen between the two scales, as well as a slight increase of the large scale length. The increase in gap size is about 0.6” (0.81” to 1.4”) from underneath the plates, and 0.58” (0.19” to 0.77”) from the red layer of the plates. Considering that the average width of an index finger is 0.78”, this allows the users to better clean the space between the plates.

The plate heights were raised from 0.125” to 0.25”, and a fillet radius of 0.25” was introduced. Although slight, this will make cleaning underneath the plates much easier. The original design had a 90-degree angle between the body surface and the raised plate.

Previously, the screen comprised of two separate plastics. To reduce the chances of food getting stuck within the cracks between each plastic component, there is now only one part. This one component will now cover the screen display and have circular cutouts for the buttons. As well as improving sanitation, this will reduce manufacturing costs.

Button placement and design have stayed the same, except for increase the size of the power button. Previously the power button was slightly smaller than all other buttons. All buttons are now of equal size and status. Although it is unable to be seen, the time before the screen turns off (while it has read the same valued weight) has been increased from 3 minutes to 5 minutes. The time before the screen turns off if the screen reads no weight at all has not changed from 1 minute.

Unlike the original design, the precision scale reading is now on top, making it directly below the precision scale itself. In order to keep the #1 on top and #2 on bottom, the precision scale is now labeled as #1, and the high capacity scale is #2. This improves the communication between the scales and the screen. User‘s eyes will not have to cross over the top numbering any more when they are using the precision scale. Additionally, the color of the text on the plates have been changed to a blackish grey, and the unit size on the screen has been slightly increased, both to improving legibility.

The last place which the increase in length can be seen is underneath the body of the scale. Previously, the finger holds on the sides were only 0.25”, making it difficult for the user to manipulate the scale. By keeping the internal mechanical design the same, we are left with an additional 0.25” on both sides. The new space for the users fingers to hold the scale is now 0.5”, left and right.