The way you connect sensors to a PC might seem trivial but if you're buying new equipment, it needs to be put at the top of a list.

In a time when you can connect to a computer in the other hemisphere, you may wonder why you can't connect to a sensor in your hand. Older logging systems connect to a computer serial port. Serial port systems require no driver software and they mostly work well. However this port is hard to find on new PCs. With an adaptor these loggers gain use today. Today sensors connect to a computer using USB. Many USB systems also use the power from the plug. This gives reliability since you've one lead and no power connection to forget about. USB is the choice way to connect today not just because most systems use it anyway, but because if you're using the same PC daily, it's reliability is near brilliant. But USB systems also need drivers. This is no problem on your laptop, but on a network you can't be sure all the workstations have the driver. So be prepared: have the driver disc to hand as well as the admin password.

Bluetooth is a wireless type of sensor connection that requires a battery in the sensors. These wireless systems are evolving but right now this is a downgrade. There's another battery to check, charge and change. Bluetooth allows you to record measurements that happen some distance away. It also helps when wires would impede some motion you need to measure. Bluetooth is now almost essential for data logging with PDA computers. The Bluetooth systems I've seen work across the room. They don't reach to the school pond or pool. On a windy day I can frankly spit further than Bluetooth. If you're keen, do some Bluetoothing between a mobile phone and a PC. If you can win against Bluetooth, go boldly forward.

The LogIT Bluetooth claims a range of up to 100 metres. This opens up some exciting applications.