Plug in a temperature sensor you bought maybe a dozen years back, and global warming or no, you can bet it’s still measuring Celcius as good as ever. But as PC systems change, and the equipment you plug sensors into improves, you can too often find that “upgrading” means you have to start over and buy all your sensors again. Technology is a sad euphemism for “disposable”.

But this year starts with joy, especially for those who own sets of LogIT sensors. Coming from Griffin and Commotion, the LogIT Datavision (pound;359) is a new generation logger with the distinction of allowing you to plug in those old probes for measuring temperature as before. What’s new is a data-logger that displays readings on a colour screen so you can distinguish lines on a graph.

Unusually, the unit lets you do a surprising amount of analysis without going near a PC, although its USB link allows easy connection. The Datavision measures rapidly too, meeting the benchmarks that physics teachers set and yet still featuring the “press-the-green-button” easiness that biology fieldwork needs. This is sensing gone sensible.

Another piece of well-thought-out equipment is Pasco’s Xplorer Datalogger PS-2000 (pound;199), a neat multi-sensor at a price to suit junior and middle school years. It does the essential tasks and comes with a USB adaptor which will allow those starting out to add on sensors from the huge PASSPort range. One of the new products Pasco will be displaying on its stand at BETT is a unit that lets you record mass from a weighing balance, which will cheer up a few chemistry experiments. In everyday reliability, which continues to be data-logging’s downfall, this range leads the way with plug and go ease.

A trend to note is that many sensor systems now work with handheld computers. With the power of these devices near that of old desktop machines, even data analysis is possible on these very portable units.

Pasco offers PowerLink, which is a handy bridge between its PASSPort range and a Palm PC that sells for under pound;100. The software is very easy too.

From Matrix Multimedia comes the Flowlog data-logger, which will also “talk” to Palm PC’s and work with a desktop PC. Intriguingly it sends data to the Palm using an infra-red link and has an identifier, so lots can be used simultaneously.

Another unit, the Trilog from Economatics, acts as a tidy base to hold the Palm PC. Uniquely, as well as sensors it comes with a mini-video camera to record the experiment. A starter kit (pound;436) includes an abundance of connectors to make it all possible.

While the Palm seems to be the portable computer of choice, Data Harvest has the Easysense Flash logger (pound;125) for those keen on Microsoft’s Pocket PC. Unusually, the accompanying software is packed with as as many features as you find on the PC. This tiny unit also works especially well plugged into laptops and Tablet PC’s. What’s more, this year the Easysense Flash logger is up for a BETT Award.

Those who’ve invested heavily in the old Philip Harris ranges can give them a new lease of life with the fast-recording Logbook ML from Sciencescope.

The sensors work seamlessly alongside Sciencescope’s own, including an interesting infrared distance sensor, which acts as an electronic ticker tape.

For the tightest budget, the SciSci data-logger from Valiant Technology is finally available at just under pound;100 for a versatile unit with a display screen. An add-on multi-sensor (temperature, light and sound) joins the trend for all-in-one sensors. Finally, Instruments Direct has the vast Vernier range for PC, Palm and Texas Instruments calculators.

Primary schools will have an easier time because nearly all the makers, such as Pasco and LogIT, offer an affordable starter kit. Data Harvest will have a new unit for the BETT show, while the Advisory Unit has what may be the first portable weather logger. Called the Kestrel 4000 Pocket Weather Tracker (from pound;335), this is a self-contained unit able to measure pressure, humidity, altitude, wind speed and more on your treks up Snowdonia.

If you arrive at BETT, be prepared for one of the biggest showcases of data-logging gear. Big and burgeoning, with lots of systems each going their own sweet way with little commonality, the only respite comes from Logotron’s Data-Logging Insight (pound;85) software, which works across many different systems. Look out for primary and secondary versions, for PC and Mac, to help you salvage yesterday’s gear.