One would require x metres. 2 multimeters and 2 gas meters wouldn't cut it.
Don't rush to go on the stand up circuit, when lockdown ends eh
now if you still want to talk meters rather than metres - what you want my friend is a frequency domain test using a cable analyser. These days typically a Fluke DSX or back in the day twas a PentaScanner.
CW1308 is .....well pretty rubbish cable to be fair. The only reason we use it is because its there (legacy), cheap and still strung up around the country.
I would encourage everyone to use at least Cat5e (or even Cat6 or 6A) as a means to reliably and properly extend networks around their homes and offices. This can also be successfully used for VDSL comms too. No issue and you then can put the £5 roll of CW1308 in the skip where it belongs, rather than your wall cavities.