BS EN 60444-1:1993 Measurement of quartz crystal unit parameters. Basic method for the measurement of resonance frequency and resonance resistance of quartz crystal units by zero phase technique in a $Gp-network
1993BS EN 60444-1:1997 Measurement of quartz crystal unit parameters. Basic method for the measurement of resonance frequency and resonance resistance of quartz crystal units by zero phase technique in a π-network
1993BS EN 60444-1:1993 Measurement of quartz crystal unit parameters. Basic method for the measurement of resonance frequency and resonance resistance of quartz crystal units by zero phase technique in a $Gp-network