The reading is not stable
Our EMG devices are carefully checked during each phase of manufacturing, and you are always getting the unit carefully calibrated by the manufacturer. When using the EMG Biofeedback device: 1. Please always be sure to use the reference electrode otherwise the EMG signal will be incorrect. 2. To avoid the effects of electromagnetic interference, never use the Biofeedback device within 4 metres of a cellular telephone, or near any other powerful radio interference producing equipment that causes electrical sparks etc. The unit may be susceptible to strong interfering radio type emissions that may lead to temporary increased EMG microvolt readings. The reading will immediately return to the correct value when the interference ceases. (Remember that a relaxed muscle should read below 3.5 μVolts). 3. Do not use the device near a laptop or computer, failing that, make sure the power adaptor is switched off at the mains, as it produces a powerful interfering field which alters the reading on the Biofeedback device.