STARTER PEN METERS Compact Design for Fast, Convenient Electrochemistry Measurement At Your FingertipsAfter more than a century of perfecting the art of measurement through our durable weighing products, OHAUS precision is now available in a line of pen meters that provide accurate measurement of pH, oxidation-reduction potential (ORP), conductivity, salinity, and total dissolved solids (TDS). Starter pen meters are the economical option when you are simply looking for meters that will provide accurate measurement without restriction.ApplicationspH, oxidation-reduction potential (ORP), conductivity, dissolved oxygen (DO), salinity, total dissolved solids (TDS), temperature measurement DisplayLiquid crystal display (LCD) display with secondary information line (on select models) Operation4 1.5V batteries (included) CommunicationN/A ConstructionABS Housing Design FeaturesEasily replaceable electrodes, automatic shut off feature