You can easily operate this lab testing instrument by following the below-mentioned steps. � You can do this by first starting this lab testing instrument and plugging it in a 3 Pin - 5 Amp. Power supply socket. Once you turn the machine ON, then the load indicator might show some readings due to previous test values. � Set the pressure to zero by pressing the TARE button and then the RESET button. Now the Load Indicator will show zero reading.