The colour-coded analogue meter indicates high or low levels of WME % moisture content of plaster or concrete over the range of 4 to 20%. A reference scale of 1 to 10 is also included for comparison readings without reference to particular...
An automatic digital polarimeter . A polarimeter  is a scientific instrument used to measure the angle of rotation caused by passing polarized light through an optically active substance  ...
A pen type pH meters  of various types  and quality can be used for soil measurements in   pH meters  range from simple and inexpensive pen -like devices to complex.  ...