Used THERMO SCIENTIFIC Orion 4 Star

Improved calibration and measurement accuracy. Easy to set up and use while delivering exceptional, long-life performance for demanding R&D and QA/QC applications.
Easy to operate in any mode
Bright, backlit LCD display with ready indication Simultaneous display of pH, mV, or ISE plus temperature
Convenient built-in Quick-Start Guide with calibration instructions
Stores, displays and prints up to 10 methods with individual method password protection
Automatic or manual temperature compensation
Auto-read/hold function
Capable of operating an autosampler or stirrer (both sold separately)
IP54 dustproof and splashproof
Extra features in every modepH: automatic or manual calibration; 1 to 5 calibration points; auto-buffer-recognition of NIST™/US and DIN buffers
ISE: manual calibration; 1 to 5 calibration points; point-to-point calibration, high and low concentration range; automatic blank correction
mV/ORP: EH autocalibration to standard hydrogen electrode
Increased accuracy
Improved stability algorithm improves calibration and measurement accuracy
SMART STABILITY™ and SMART AVERAGING™ functions optimize accuracy, precision and response time
ATC calibration
Advanced self-tests on meter operation, self-diagnostics
Complete documentationFull complement of GLP-related features
Optional Star Plus Navigator 21 software provides 21 CFR Part 11, GLP IQ/OQ documentation
1000 point datalogger, downloadable to printer or computer via RS-232 connection
Average slope and slope of segment printed with measurement