Yes, true .. that tool named ohmmeter or multimeter, but not the usual but rather a multi-meter multimeter with true RMS facility, because if you measure the output power of modified sine wave inverter with a multimeter is not the usual result SURE but 190Volt 220Volt
Therefore if you have a modified sinewave power inverters you must measure it with a multimeter TRUE RMS facility in order to obtain accurate results for 220Volt