"I have owned this meter for almost 8 years and only replaced the probe once

and any application requiring extended cable reach and rugged construction

Industrial cooling tower water treatment

bright tri-color LED display (green

Hanna Ammonia Medium Range CAL Check Standards for HI97715 RO TDS tester "I have owned this meterThe HI97715 11 Ammonia Medium Range CAL CheckTM Standards provides a simple solution to calibrating and validating the HI97715 ammonia medium range photometer. This high quality set of standards is manufactured in our state of the art facility and comes supplied with a certificate of analysis. The certificate of analysis provides the lot number, reference values and expiration date for traceability when certifying the HI97715 photometer. Supplied with