Convenient time-interval recorder eases the lab work The SP-2500 is compatible with GLP requirement. There are built-in calibration timer and counter for reminder to make sure the validity of your measurements. The advanced up-to-five point linear regression calibration provides for the most demanding research. The advanced data logger function allows the meter automatically save the measurement with time interval up to 500 sets and can direct transmit the data through RS-232 interface to a computer or a printer. Thus, the user may leave until the work is done. The front membrane keypad matches IP43 level waterproof protection to prevent accidental leak of sample solution. The SP-2500 features ion selective method & direct reading of ppm unit.