1) Carbon dioxide measurer 2) Carbon-dioxide monitor 
<physiology> A device which is used to measure the tiny amounts of carbon dioxide that functioning tissues give off. ... (21 Mar 1998) ... 
Type: Term Pronunciation: bī-om′ĕ-ter Definitions: 1. A device for measuring carbon dioxide given off by organisms and, hence, for determining the quantity of living matter present.
biometer 1. A device for measuring carbon dioxide given off by organisms and, hence, for determining the quantity of living matter present. 2. An instrument by which minute quantities of carbon dioxide can be measured; used in measuring the carbon dioxide given off from functioning tissue. Re...
an instrument for measuring the amount of carbon dioxide given off by an organism, tissue, etc.