In these days when you can connect to a computer in the other hemisphere, you may wonder why you might not be able to connect to a sensor that is 50cm away. To be accurate the ease of doing this has improved these last 5 years. In pages nearby we'll talk about what learning might come of this and practically what we do. This section is about the distraction of choosing equipment.

The way you connect a data logger to a PC might seem trivial. However experience suggests that we put it near the top of a feature list where we consider hardware; software; support and how smiley is the sales rep.

Older logging systems connect to a serial port but this socket is hard to find on new PCs. With an adaptor these loggers gain use today - furthermore, serial systems require no driver software and mostly they work. Today's way to connect uses USB and many USB connected systems also provide power in the plug. The power feature gives reliability in a one-lead connection. But USB systems also need drivers - these work well on 'my' laptop, but on a network you'd best be prepared: have the driver disc to hand as well as the admin password. USB is the choice way to connect today not just because you've little choice, but because if you're using the same PC daily, it's reliability is near brilliant.

Bluetooth is a wireless connection that requires battery power in the sensors. These wireless systems will no doubt evolve but right now this is a downgrade step for reliability: there's another battery to check, charge and change. Bluetooth allows you to record measurements happening some distance away or when wires impede the motion of a trolley. It's now almost essential for logging with PDA computers. Three systems I've seen work across the room but not as far as the school pool. Excuse the analogy, but on a windy day I can spit further than Bluetooth. The LogIT Bluetooth claims a range of up to 100 metres which opens up some exciting applications. If you're keen, do some Bluetoothing between a mobile phone and a PC. If you can win against the Bluetooth connection software, go boldly forward.