the Testo 454 datalogger has integrated memory. Up to 10 parameters can be saved on location. The Testo 454 automatically recognizes the probes. Software is available for data analysis on a PC.
 

Memory space	256 kB (corresponds to 114 000 measured values)
Alarm output	Electrically isolated open collector outputs
Max. load current	50 mA (internal limit)
Max. permissible power	240 mW
Max. permissible voltage	30 V (6 V with polarity reversal)
Trigger
Max perm. voltage	10 V
Actuating shaft	4 to 10 V
Input load	20 mA (with 10 V)
Programmable channel settings	Unit Scaling  Calibrating Max. 6 probes simultaneously Max. 4 probes simultaneously when ball velocity probes are connected
Power supply	6 cell rechargeable battery, built-in or via 12 V power supply
Battery supply
Continuous operation with 6 PD probes	8h
10 minute measuring rate	11 days
Operating Temperature	-15 to 50°C (0 to +122 °F)  Short Term -15 to 60°C (0 to +140 °F
Storage and transport temperature	-30 to 60ºC (-22 to + 140°F)
Connection	Standard flanged bushing
Weight	1.4 lb. (including battery)
Other	Automatic recognition of all the probes connected Housing material ABS
Warranty
Measuring Instrument	3 years