I'm trying to measure precisely E4417A power meter's 50 MHz/1mW RF reference output using HP 432A power meter with 478A thermistor mount.
I have followed 432A's user guide note how to make precision power measurement taking account those Vcomp and VRF voltages. I have one
Agilent 34401A DVM for that purpose. Main problem is that those Vcomp and VRF values are not stable even i have made Coarse and Fine zeroes for the meter.
All equipment's locates temperature stable laboratory (23 +/ 1 celsius). Many user guides says to use more precisise Agilent 3458A DVM. Is 34401A still enought precise for those Vcomp and VRF measurements?
Should i take account something special how to zero 432A meter first and how to connect those Vcomp and Vrf output's to 34401A voltage inputs? I have only one DVM where i have connected Vrf to DVM's rear input and Vcomp to front input connectors using BNC cable's where another end has suitable banana connectors.
If someone have practical hints or advices for such a precision power measurements, please let me know.
I have followed 432A's user guide note how to make precision power measurement taking account those Vcomp and VRF voltages. I have one
Agilent 34401A DVM for that purpose. Main problem is that those Vcomp and VRF values are not stable even i have made Coarse and Fine zeroes for the meter.
All equipment's locates temperature stable laboratory (23 +/ 1 celsius). Many user guides says to use more precisise Agilent 3458A DVM. Is 34401A still enought precise for those Vcomp and VRF measurements?
Should i take account something special how to zero 432A meter first and how to connect those Vcomp and Vrf output's to 34401A voltage inputs? I have only one DVM where i have connected Vrf to DVM's rear input and Vcomp to front input connectors using BNC cable's where another end has suitable banana connectors.
If someone have practical hints or advices for such a precision power measurements, please let me know.
you can't use the front and rear DMM inputs simultaneously - there is a switch to set which inputs are active. Connections are either both in the front, or both in the rear.
the cable should connect the center conductor of the 432A BNC connector to one banana jack on the 34401A. You do not connect the ground (outer conductor) of the BNC jack to the DMM. You will probably need to use adapters or make a special cable.
I am not sure about the accuracy of the 34401A. There is an uncertainty analysis of the procedure in the E4418B service guide:
http://cp.literature.agilent.com/litweb ... -90059.pdf
the test procedure is on page 2-17, and further information is in Appendix A and Appendix C. Use the Appendix C analysis to see if the DMM accuracy is adequate.