Measuring power usage over time? What kit is that?

Hi,

I have a simple project in which my Espruino wakes up every 2 seconds and takes a reading from a magnetometer, if the conditions are right, it wakes up an nfr2401 radio and sends a signal.

All OK and is very good, but I am trying to estimate how long a LIPO battery will last.

I put my multimeter into the correct mode, and put it in-line (?) (measure current ftw) between the LIPO and the Espruino, and fair enough I can see the numbers change as the current surges when the reading is taken and the radio is required to TX, i.e. from almost nothing to a jump then back down again in a blur.

What is the name of the equipment I would need to monitor and log this usage properly, say over a 5 minute period? (some expensive piece of kit no doubt)

What is the poor man's version of that?

I imagine this must be a common practice, how do you set up your workbench to monitor current use as you work?

Thanks!