Operation range^†: -40° to 70°C (-40° to 158°F) in air; maximum sustained temperature of 50°C (122°F) in water Accuracy: ±0.21°C from 0° to 50°C (±0.38°F from 32° to 122°F) Resolution: 0.02°C at 25°C (0.04°F at 77°F) Response time: (90%) 5 minutes in water; 12 minutes in air moving 2 m/sec (typical) Stability (drift): 0.1°C (0.18°F) per year Real-time clock: ± 1 minute per month 0° to 50°C (32° to 122°F) Battery: 2/3 AA, 3.6 Volt Lithium, factory-replaceable ONLY Battery life (typical use): 6 years with 1 minute or greater logging interval Memory (non-volatile): 64K bytes memory (approx. 42,000 12-bit temperature measurements) Weight: 42 g (1.5 oz) Dimensions: 3.0 cm (1.19 in.) maximum diameter, 11.4 cm (4.5 in.) length; mounting hole 6.3 mm (0.25 inches) diameter Wetted materials: Polypropylene case, EPDM® o-rings, stainless steel retaining ring Buoyancy (fresh water): +13 g (0.5 oz.) in fresh water at 25°C (77°F); +17 g (0.6 oz.) with optional boot Waterproof: To 120 m (400 ft.) Shock/drop: 1.5 m (5 ft.) drop at 0°C to 70°C (32°F to 150°F) Logging interval: Fixed-rate or multiple logging intervals, with up to 8 user-defined logging intervals and durations; logging intervals from 1 second to 18 hours. Refer to HOBOware software manual. Launch modes: Immediate start and delayed start Offload modes: Offload while logging; stop and offload Battery indication: Battery voltage can be viewed in status screen and optionally logged in datafile. Low battery indication in datafile. NIST certificate available: for additional charge Environmental Rating: IP68The CE Marking identifies this product as complying with all relevant directives in the European Union (EU).^†IMPORTANT: The plastic case will become brittle at temperatures lower than -20°C. If the logger is deployed in a location where the temperature drops below -20°C, make sure the logger remains stationary and is not pulled on or struck. Return the logger to above -20°C before handling.