Physics will appreciate this top of the range data logger (see pic) capable of fast logging (20µs or 50000 samples a second). There’s an easy menu screen, six sensor sockets, and a large memory to store multiple sets of readings. It comes in two flavours where you can connect to a PC with USB and Bluetooth or just USB. Battery life is reliably long and it recharges while connected to the computer.

For the ultimate in simplicity go for this interface which can use three sensors at once. It connects to the PC, and gets its power via the USB cable. And best of all it has no buttons and yet it’s capable of fast data capture (up to 40,000 readings a second). Those that go out and monitor in the field might consider getting one or two of the EasySense loggers with batteries and memory since 'Q link' only works while connected to a PC.

EasySense Q3+: has built-in sensors that record Sound, Light and Temperature so that you pick this box up and start measuring without connecting anything. It has a simplified menu screen which suits it well to primary school use. It's available as a primary data logging pack (see pic) with sensors and a nice book of ideas for classroom activities. So used, its two SmartQ sensor sockets, should be sufficient. Comes in two flavours where you can connect with USB and Bluetooth or just USB. The battery recharges while the data logger is connected to the computer.
                                 
EasySense Q5+ is an enhanced version of the Q3+ that shares the same simplified menu screen, rechargeable battery and memory. It is designed for recording environmental data so the Q5+ has five built-in sensors that record Sound, Light, Temperature, Pressure and Humidity. Otherwise as for Q3+

Comment: the Q3+ and Q5+ are as functional as primary science needs. They are a major improvement on a past product ('Ecolog'). The Easy Sense software outshines its competitors. Quibbles are minor – their box shape suits tabletop work, not portability; the built-in screen is a couple of lines short of useful and the manual is overlong for something so easy to use.

If you are looking for ‘small’, the EasySense Flash Logger is one of the most compact ‘loggers’ you can find. It slots into a socket found on some Pocket PC devices as made by Hewlett Packard. It then connects to Data Harvest’s ‘SmartQ’ sensors to do any experiment you would care to do. The Flash Logger is unique in that it connects to Compact Flash. The result of putting the Flash Logger and PocketPC together is a computer and data logger with three sensor sockets. The EasySense software is very functional. You gain a lot of power in a tiny package. The software is very similar to what normally runs on a full size PC so you can be doing a lot without using a manual. It’s even worth having a Flash Logger to plug into a laptop because you can measure without need for an extra power adaptor (you need only a PC card socket and inexpensive adaptor to do this). A very interesting and award-winning solution. It merits a bit of research to see whether your choice of PocketPC needs to be on charge to retain the program in memory. The EasySense Flash Logger is part of the Graphical Logger Pack – an all-in-one solution including a PocketPC with pre-installed EasySense software.
See TES review

A dedicated stand-alone digital timer and interface with 2 digital sensor sockets for light gates, pressure pads or switches. The Qt is an interesting choice offering simplicity if all that’s interesting is measuring time, velocity, acceleration, kinetic energy and momentum. Comes in Bluetooth and USB, or just USB versions. The Qt Digital Timer is part of Qt Total Timing which includes Data Harvest’s Dynamics System and Light Gates in one package.

This track with a support stand is an elegant way to do dynamics experiments. While there’s no electronics to discuss, we do commend this substitute for traditional ramps and all their awkwardness. Comes with a cart (trolley), brackets and thumbnuts. We really like this high quality, modular track. All you need is Light Gates and an interface so this can work with other manufacturers systems. You could do a fantastic variety of core physics activities. The documentation spoils it: when you’re in a hurry to set up you just need a photo to see what to do.
                                                                        
Dynamics System Extension Pack 1 - lab apparatus
An additional cart, magnets, springs and extra brackets. Also has a set of interrupt cards to pass through light gates and measure time, speed and so on. For example there is a picket fence that lets you investigate collisions, forces and acceleration. Requires Light Gates.

The Data Harvest range uses SmartQ sensors that measure temperature, light, position, sound, conductivity, voltage, and pH. Light gates can time events in experiments with trolleys, ramps and so on. Many other sensors are available including a low range pressure sensor that is great for biology. All these sensors have a chip which tells the software what they do and neatly works round the need to upgrade the software when you buy a new sensor. This works well in practice. Data Harvest also has a heart rate monitor and magnetic field sensor. There’s a motion sensor – great for distance time graphs and there’s a colorimeter to measure reaction rates in chemistry and biology with finesse. Overall the sensor range meets any need.
EasySense SmartQ sensors use a mini-DIN type connector. Prior to 2002 the tiny pins on these would bend over. This was soon rectified and today’s sockets have a collar to guide the plugs.

Data Harvest - EasySense (1998) These loggers are very good indeed and are worth using even today if the PC offers a serial connection. Later models introduce USB connections (above). A USB-serial connector can be used to get these working on today’s PCs.

Data Harvest - EasyLog and Sense and Control (1990) Two previous series of interface boxes still work today although there is no compatibility between them and the current system.

Data Harvest – Ecolog - Data Harvest’s pocket-size Ecolog system for primary schools is now sold by Fourier. It worked with ‘Junior Insight’ software as well as Data Harvest's own ‘Sensing Science Primary’ software. Battery life is a common issue with equipment that’s stored for long periods. Store a battery tester and fresh batteries nearby and it works out fine.