ACCURACY
3-5
L + Q ACCURACY
Accuracy of L = ± [A x Ki x Kv + (Kh + Kl) x 100] %
A
=
Basic Inductance Accuracy Factor
from graph.
For Q < 10, multiply the basic
accuracy factor by (1 + 1/Q).
If the unit is in the constant voltage
(CV) mode, double the basic
accuracy factor.
Ki
=
Integration Time Factor (see Ki
Table below)
Kv
=
Voltage Error Factor (see Kv table
below).
Kh, Kl
=
Extreme Range Error Term (see
Kh, Kl table below).
Accuracy of Q = ± [(Al / 100) x (1 + Q2)]
Al
=
the accuracy of the Inductance
measurement (above)
Note that the accuracy of Q is specified as a
magnitude, NOT as a percent.
Ki Table
Meas Rate Frequency Zm
Ki
slow, med all
1
fast
100 Hz-1 kHz 6.25
Ω
<Zm<400 k
Ω
3
fast
all other
2
Zm = 2
π
fL = impedance of device
Kv Table
Vout (V rms)
Kv
1.0 - 0.55
1 / Vout
0.5 - 0.3
0.5 / Vout
0.25 - 0.15
0.25 / Vout
0.10
0.11/Vout
Note that Kv equals one for the primary drive
voltages (1.0, 0.5 and 0.25 Vrms).
Kh & Kl Table
Frequency
Kl
Kh
100,120 Hz
(1
µ
H / Lm)
(Lm / 2.6 MH)
1 kHz
(0.1
µ
H / Lm)
(Lm / 260 kH)
10 kHz
(0.02
µ
H / Lm) (Lm / 10 kH)
100 kHz
(0.02
µ
H / Lm) (Lm / 100 H)
Lm = the inductance of the device being
measured.
Note that Kl is negligible for inductances above
15.9/f H and Kh is negligible for inductances below
159./f kH, where f is the output frequency.
