Strange LCR meter readings

[pigkiller]

few days ago,i wanna measure L of a on chip spiral inductor.
i tune the LCR meter,freq=1kHz,current=1mA,and did the open and short(DC Probe connection) calibration. ALC on.
but the value is 3.xx uH !!
the DC value is about 25nH.
why?

 

[g579]

lcr meter theory

You should try some resonance method in the GHz range.
For very small inductances LCR meters are unusable

 

[AL0117]

q meter bm409

You should use some resonance method at RF freqs, as g579 said.
I am using my old/good Tesla BM409 Q-meter. It hasn't direct inductance readout, but is a great instrument to measure inductance, capacitance and Q factor up to 300 MHz.
If you have a good RF generator, you could breadboard the rest. Take a look at
hxxp://www4.tpgi.com.au/users/ldbutler/QMeter.htm
(x=t)

for the theory and practice of a Q meter.

regards, Al