Trumeter process meter with trurange technology trumeter apm proc apo the apm apm proc apo is a positive lcd process meter that features an easy to read display along with a versatile input that works with many industrial sensors this process meter takes apm into a wide range of new applications the programmable scale and custom annunciator means users can tailor the meter to display their critical parameters exactly how they want whilst the dynamic backlighting in conjunction with setpoi