Hanna Instruments HI-98128 pHep5 pH/Temperature Tester 

Model HI 98128 (pHep 5): This Hanna Instruments waterproof tester features a dual-level LCD that gauges pH level -2.00 to 16.0, and temperature from 23.0 to 140.0 °F (-5.0 to 60.0 °C). 

It provides a battery level indicator with an automatic shut-off after 8 minutes of non-use. Batteries last for about 300 hours of continuous use. The pH Electrode Cartridge is replaceable!

Automatic calibration and stability indicator are also standard on this Hanna Instrument tester. Its not only waterproof - it floats!

Stats:

pH Range: -2.00 to 16.00 pH
Temperature Range : 23.0 to 140.0°F (-5.0 to 60.0°C)
pH Resolution: 0.01
Temperature Resolution: 0.1°C / 0.1°F
pH Accuracy: ±0.05 pH
Temperature Accuracy: ±0.5°C / ±1°F
Temperature Compensation: Automatic
Battery Type / Life: 4 x 1.5V with BEPS / apprx. 300 hours continuous use
Environment: -5 to 50°C (23 to 122°F); RH max 100%
Dimensions: 6.4" x 1.6" x 1.0" (163 x 40 x 26 mm)
Weight: 3.5 oz. (100 g)

Certified ISO 9001. The Hanna Instruments HI-98128 Waterproof pH/Temperature Tester is a rugged piece of equipment that you can rely upon. Comes with protective cap, electrode removal tool, batteries and instructions. One (1) year manufacturers warranty.

Read Instruction Manual (PDF format - Lots of detail.)