I decided to design a new shield including the spectrophotometer beside some small modifications like gain control for the respiration sensor and a gas sensor to analyze the exhalation gases . After the shield and spectrophotometer is finished, I will focus on software and wetware for the tricorder. Things will slow down a bit as I will soon move to Germany with my family and I have to leave all my equipment and my chemistry lab here in China.

To save place, the push button interface had to be removed. I am using a joystick-like interface in a very small package instead:

One reason why I am using a respirator- half-mask for the respiration rate sensor is that I am able to do a analysis of the exhalation gases at the same time. This can be done by one or more common available MQ-series gas sensors, which are attached to 3-D printed gas chambers with a predefined volume: