Hello guys, I have a clamp meter with precision of 0,1A. I tried to measure the AC current which a battery charger draws from the mains (220V) but it is too low (0,2A-0,3A) so I made a coil to boost the measurement precision to 0,01A. I thought that the coil must have 10 turns but in fact it needed 8 turns. I made a test with two identical clamp meters (one on the coil and the other on the wire next to the coil) and the result is great. However I need to know is there a problem if the current passes trough the coil all the time untill the battery is fully charged (it may take several hours) or I have to make a switch to pass the current trough the coil only when I want to measure it and then switch it back trough straight wire?