Agilent 4268A Data Sheet

1. Basic Specifications

Measurement parameters

• Cp-D, Cp-Q, Cp-Rp, Cp-G

• Cs-D, Cs-Q, Cs-Rs

Where:
Cp: Measured capacitance value using the parallel

equivalent circuit model

Cs: Measured capacitance value using the series

equivalent circuit model
D: Dissipation factor
Q: Quality factor (inverse of D)
G: Measured equivalent parallel conductance

using the parallel equivalent circuit model
Rp: Measured equivalent parallel resistance using

the parallel equivalent circuit model
Rs: Measured equivalent series resistance using

the series equivalent circuit model

Measurement conditions

• Measurement signal

Frequency 120 Hz ±1%, 1 kHz ±0.05%
Level 0.1 V to 1.0 V, resolution 0.01 V,

accuracy ±10%
Output mode Continuous, synchronous
Source delay time 0 to 1.000 s, resolution 1 ms

(Effective when Output mode

is set to the synchronous

mode)

• Measurement cable length: 0 m, l m, 2 m

(N.B., DC resistance of H

CUR

and L

CUR

cable :

0.3 Ω or less per cable)

• Measurement time mode: Short, Med, Long

• Measurement range selection: Automatic (Auto),
manual (Hold)

• Measurement range:
When the measurement frequency is 120 Hz:
10 nF, 100 nF, l µF, 10 µF, 100 µF, 1 mF.
When the measurement frequency is 1 kHz: 1 nF,
10 nF, 100 nF, 1 µF, 10 µF, 100 µF.

• Averaging: 1 to 256 times

• Trigger mode: Internal (INT), manual (MAN),
external (EXT), bus (BUS)

• Trigger delay time: 0 to 1.000 s, resolution 1 ms

Display range of measurement value

Parameter Display range of measurement value

Cs, Cp –9.9999 mF to –0.0001 nF, 0, 0.0001 nF to 9.9999 mF

D –9.9999 to –0.0001, 0, 0.0001 to 9.9999

Q –9999.9 to –0.1, 0, 0.1 to 9999.9

Rs, Rp –999.99 MΩ to –0.01 mΩ, 0, 0.01 mΩ to 999.99 MΩ

G –9.9999 kS to –0.0001 µS, 0, 0.0001µS to 9.9999 kS

∆% –999.99% to –0.01%, 0, 0.1% to 999.99

Measurement accuracy

The accuracy is defined when all of the following
conditions are met.

• Warm up time is 30 min or more.

• The OPEN and SHORT corrections have been
performed.

•D ≤ 0.5

Agilent
4268A
120 Hz/1 kHz Capacitance Meter

Data Sheet

2

Accuracy of Cp and Cs

Accuracy Ae [%], which is the base of the accuracy
of Cp and Cs (Cpe and Cse [%]), is calculated as
follows:

Equation 1: Equation to calculate Ae

Ae = [A + B + KL3β+ l00 3 E 3 (2 3π3f 3 Cx)] 3 K

T

Where:
β = Cr/Cx when Cr ≤ 100 µF (@120 Hz) or

Cr ≤ 10 µF (@1 kHz)

β = Cr/Cx + Cx/Cr when Cr = l mF (@120 Hz) or

Cr = 100 µF (@1 kHz) (n.b., if β <1, β =1)

Cx: Measurement value of Cp or Cs
Cr: Measurement range (1 nF, 10 nF, 100 nF, 1 µF,

10 µF, 100 µF, 1 mF)

f: Measurement frequency
A: Proportional error term

(values are shown in Table 3)

B: Offset error term

(values are shown in Table 3)

KL: Coefficient for measurement signal level

(values are shown in Table 1)

E: Residual when shorted, the value is E = 600 µΩ

(fixed)

KT: Coefficient for ambient temperature

(values are shown in Table 2)

Table 1. Coefficient caused by measurement signal level, KL

Measurement signal level, Level [V] K

L

0.1 to 0.3 0.3/Level

0.31 to 0.5 0.5/Level

0.51 to 1.0 1.0/Level

Table 2. Coefficient caused by ambient temperature, KT

Ambient temperature T [°C] K

T

0 ≤ T < 18 3

18 ≤ T ≤ 28 1

28 < T ≤ 55 3

Table 3. Proportional term A and offset term B

Cr (measurement 120 Hz 1 kHz
range) SHORT MED LONG SHORT MED LONG

1 nF A — — — 0.18 0.14 0.14

B — — — 0.062 0.052 0.049

10 nF A 0.28 0.14 0.14 0.18 0.14 0.14

B 0.1 0.054 0.05 0.041 0.036 0.035

100 nF A 0.28 0.14 0.14 0.18 0.14 0.14

B 0.077 0.037 0.035 0.041 0.036 0.035

1 µF A 0.28 0.16 0.16 0.18 0.14 0.14

B 0.077 0.037 0.035 0.041 0.036 0.035

10 µF A 0.28 0.16 0.16 0.18 0.14 0.14

B 0.077 0.037 0.035 0.041 0.036 0.035

100 µF A 0.4 0.4 0.4 0.4 0.4 0.4

B 0.077 0.037 0.035 0.066 0.049 0.044

1 mF A 0.8 0.8 0.8 — — —

B 0.106 0.052 0.045 — — —

Cpe and Cse [%] are derived from the calculated
accuracy Ae [%], using the equation “Cpe = Cse =
±Ae [%].” Note that if the measured D value, Dx,
exceeds 0.1, multiply Cpe and Cse by (1 + Dx2).

NOTE: If the secondary parameter is not D,
calculate D using the equation in Table 4.

Table 4. Calculating D

Measurement parameter Equation to calculate D

Cp-Q, CS-Q D = 1/Qx

Cp-G D = Gx/(2 3π3f 3 Cpx)

Cp-Rp D = 1/(2 3π3f 3 Cpx 3 Rpx)

Cs-Rs D = 2 3π3f 3 Csx 3 Rsx

In Table 4, Cpx, Qx, Gx, Rpx, Csx, and Rsx are
measured values, and f is the measurement
frequency.

3

Accuracy of D

The accuracy of D, De, is calculated as follows,
using Ae [%]:

Equation 2: Equation to calculate De when Dx < 0.1 and
Ae ≤ 10 [% ]

De = ±Ae/100

Equation 3: Equation to calculate De when 0.1 < Dx ≤ 0.5
and Ae ≤10 [% ]

De = ±(Ae/100) 3 (1 + Dx) 3 1 + Dx

2

NOTE: The accuracy of D is expressed in an
absolute value, instead of a percentage.

Accuracy of Q

The accuracy of Q, Qe, is calculated as follows,
using the accuracy of D, De:

Equation 4: Equation to calculate Qe

Qe = ±Qx23 De/(1 7 Qx 3 De)

Where: Qx is the measured Q value. Note that if
Qx 3 De is 1 or more, Qe = ±∞.

NOTE: The accuracy of Q is expressed in an
absolute value, instead of a percentage.

Accuracy of G

The accuracy of G, Ge [%], is calculated as follows,
using the base accuracy for Cp, Ae [%]:

Equation 5: Equation to calculate Ge

Ge = ±Ae/(Gx/(2 3π3f 3 Cpx))

Where: Gx is the measured G value, Cpx is the
measured Cp value, and f is the measurement
frequency. Note that, if Dx exceeds 0.1, multiply
Ge by (1 + Dx2).

Accuracy of Rp

The accuracy of Rp, Rpe [%], is calculated as
follows, using the accuracy of G, Ge [%]:

Equation 6: Equation to calculate Rpe

Rpe = ±Ge/(1 7 Ge/100)

Note that if Ge is 100[%] or more, Rpe = ±∞ [%].

Accuracy of Rs

The accuracy of Rs, Rse [%], is calculated as follows,
using the base accuracy for Cp and Cs, Ae [%]:

Equation 7: Equation to calculate Rse

Rse = ±Ae/(2 3π3f 3 Cpx 3 Rsx)

Where, Rsx is the measured Rs value, Csx is the
measured Cs value, f is the measurement frequency.
Note that, if Dx exceeds 0.1, multiply Rse by (1 + Dx2).

4

Measurement support functions

• Measurement signal level monitor function

The measurement voltage and measurement
current can be monitored.

• Correction function

The OPEN correction, SHORT correction, and
LOAD correction are available.

• Display

40-digit 3 2-line LCD display.

• Deviation measurement function

Deviation from the reference value and the
percent deviation from the reference value can
be outputted as the result.

• Comparator function

Bin sort: Primary parameters can be sorted into
9 Bin, Out of Bins, and Aux Bin; the secondary
parameters into High, In, and Low.

Limit setting: absolute mode, absolute tolerance
mode, percent tolerance mode.

Bin count: 0–999999 can be counted.

• Save/recall function

Up to ten setting conditions can be
saved/recalled using the built-in nonvolatile
memory.

• Resume function

The instrument setting is automatically saved at
power-off.

• Key lock function

The front-panel keys can be disabled.

• Contact check function

Automatic detection of contact failure between
the measurement terminal and the DUT.
(Available in the 4-terminal measurement)

• GPIB interface

Compliance with IEEE 488.1,2 and SCPI.

• Handler interface

Negative-logic input/output signals. Opto-isolated
open collector signal.

Output signals Bin 1-Bin 9, Out of Bins,
Aux_Bin, P-Hi, P-Lo, S-Reject, INDEX, EOM,
Alarm, OVLD, NC.

Input signals Keylock, Ext-Trigger.

• Scanner interface (Option 4268A-001)

The OPEN/SHORT/LOAD correction of sixty-four
channels are available.

NOTE: The 4268A has the following interface options.

Option 4268A-001: GPIB/handler/scanner interface
Option 4268A-002: GPIB/handler interface

5

Power supply

Voltage 90 VAC to 132 VAC, 198 VAC

to 264 VAC

Frequency 47 Hz to 66 Hz

Power consumption 40 W maximum/100 VA

maximum

Operation conditions

Temperature 0 °C to 45 °C

Humidity (≤ 40 °C,
without condensation) 15% to 95% RH

Altitude 0 m to 2000 m

Non-operation conditions

Temperature –40 °C to 70 °C

Humidity (≤ 65 °C,
without condensation) 0% to 90% RH

Altitude 0 m to 4572 m

EMC

• Compliance with CISPR 11(1990)/EN 55011
(1991): Group 1, Class A

• Compliance with EN 61000-3-2 (1995)/IEC
61000-3-2 (1995)

• Compliance with EN 61000-3-3 (1995)/IEC
61000-3-3 (1994)

• Compliance with EN 50082-1 (1992)/IEC 61000­4-2 (1995): 4 kV CD, 8 kV AD

• Compliance with EN 50082-1 (1992)/IEC 61000­4-3 (1995): 3 V/m, 80% AM, 27 MHz to 1000 MHz

• Compliance with EN 50082-1 (1992)/IEC 61000­4-4 (1995): 0.5 kV Signal Lines, 1 kV Power
Lines

Safety

• Compliance with IEC 61010-1 (1990) +A1 (1992)
+A2 (1995), CAN/CSA C22.2 No.1010.1-92

2. General Specifications

6

Outer dimensions

Approximately 320 mm (W) 3 100 mm (H) 3 450 mm (D)

Figure 1. Front View

Figure 2. Rear View

Figure 3. Side View

Weight

Approximately 5 kg

7

This section shows the reference data related to
the operation of the 4268A other than the specifi­cations.

The data are not specifications but typical charac­teristics useful to operate the instrument.

ALC (Auto Level Control) function

Operating measurement range setting

When the measurement frequency is 120 Hz:

100 µF range, 1 mF range

When the measurement frequency is 1 kHz:

10 µF range, 100 µF range

If the ALC is to operate below its measurement
range, the output of the signal voltage level will be
judged depending upon whether the conditions
below are satisfied or not.

Vset 3 0.9 < Vmon < Vset 3 1.1
Vset: measurement signal voltage setting
Vmon: Applied signal voltage to the DUT

Operating range

3. Supplemental Performance Characteristics

Table 5. Operating range of the ALC

DUT Measurement voltage

Measurement frequency Dissipation factor Capacitance C Minimum Maximum

120Hz D ≤ 0.2 C ≤ 600 µF 0.1 V 1.0 V

600 µF < C ≤ 1200 µF 0.1 V (600 µF/C)V
C > 1200 µF Out of range

0.2 < D ≤ 0.5 C ≤ 600 µF 0.1 V 1.0 V
C > 600 µF Out of range

D > 0.5 All Out of range

1 kHz D ≤0.2 C ≤ 70 µF 0.1 V 1.0 V

70 µF < C ≤ 140 µF 0.1 V (70 µF/C)V
C > 140 µF Out of range

0.2 < D ≤ 0.5 C ≤ 70 µF 0.1 V 1.0 V
C > 70 µF Out of range

D > 0.5 All Out of range

Figure 4. Operating range of the ALC function

8

Measurement time

Table 6 shows the measurement times when the
measurement settings are as follows.

Display Off
Measurement range mode Hold
Averaging 1
Source delay time 0 ms
Trigger delay time 0 ms

Table 6. Measurement time

Short Med Long

Measurement time Min. Max. Min. Max. Min. Max. Unit

T1 Analog 16 19 34 37 50 53 ms

measurement time (20) (23) (38) (41) (54) (57)

T2 Measurement 20 25 38 43 54 59 ms

time (24) (30) (42) (48) (58) (64)

The values in ( ) are the measurement times when
the contact check function is ON.

Measurement range

The recommended measurement range and
effective measurement range are shown in
Table 7 (where the dissipation factor D ≤ 0.5).
Recommended Measurement Ranges are given
for better measurement accuracy while Effective
Measurement Ranges are provided to avoid
overloads.

Contact check function

Effective measurement range

(D ≤ 0.5)

Minimum contact impedance that can be detected

5 MΩ

Table 7. Measurement range of capacitance

Recommended measument range [F] Effective measament range [F]

Measurement Measurement Measurement Measurement

Measurement range frequency: 120 Hz frequency: 1 kHz frequency: 120 Hz frequency: 1 kHz

1 nF — 0.2 n to 2 n — 0 to 2 n

10 nF 2 n to 20 2 n to 20 0 to 20 n 0 to 20 n

100 nF 20 n to 200 n 20 n to 200 n 0 to 200 0 to 200

1 µF 0.2 µ to 2 µ 0.2 µ to 2 µ 0 to 2 µ 0 to 2 µ

10 µF2 µ to 20 µ 2 µ to 20 µ 0 to 20 µ 0 to 20 µ

100 µF 20 µ to 200 µ 20 µ to 200 µ 0 to 200 µ 0 to ∞

1 mF 0.2 m to 2 m — 0 to ∞ —