A datalogger is not just for Xmas

We come to expect computers to change often and get us to upgrade but with data loggers I wonder. The need to take readings from experiments is pretty much the same today as it was fifteen years ago. In other words the kit you had then really ought to work now. I am still looking for a good reason any firm should change the design of a temperature sensor. The reason for change that I can see is to seek something more reliable.
My day job - providing courses on data logging and the use of ICT in science - has been much enhanced by the amount of Philip Harris equipment in schools. The equipment, consisting of 'Blue Box' sensors, DL Plus interfaces, First Sense, CL100 card loggers was bought by the lorry load during the 1990's. The system was changed many times and at great cost to science dept budgets. ().
These kits have been very troublesome too - most often the problem is an iffy link between the box and the sensors - leads, battery power and serial ports each playing their part in an unreliable setup.
"Surely the technology has moved on and got better" said the last school I visited so I took along samples from various manufacturers to see if it had. Most impressive were the USA made systems from Vernier and PASCO. Each worked via the USB port - the software responding immediately to plugging and unplugging sensors. LogIT and Data Harvest systems were fairly good though you needed to get the software at the right place before it would recognise the sensor had changed. Of the two LogIT was most responsive - what spoiled it for the Data Harvest box was to complain about a lack of a driver - even though I'm sure I'd installed this beforehand.
If you're having problems with whatever you bought it is possible to continue using the existing kit reliably:
1) Get each part of the kit working before connecting up to the PC.
2) Be prepared to discard (or mark as suspect) some items.
3) If the effort required is discouraging, rest assured there is good equipment to be had.
4) Whoever you buy from, look at their track record and wonder why they've changed their system so many times.