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The Keysight 4285A Precision LCR Meter is a benchtop impedance measurement instrument that characterizes passive components and materials across a 75 kHz to 30 MHz test signal range. It measures the full set of impedance parameters — |Z|, |Y|, L, C, R, G, D, Q, Rs, Rp, X, B, and phase angle — under user-programmable test signal and equivalent-circuit conditions, with both series and parallel measurement models available. The instrument uses a four-terminal pair connection at the UNKNOWN terminals and supports selectable test cable lengths of 0 m, 1 m, or 2 m with corresponding cable correction.
The 4285A is built for component characterization, incoming inspection, and production component sorting where the device under test must be measured across a defined frequency range with controlled signal level. Its ten-bin comparator function supports both sequential (unnested) and tolerance (nested) sorting modes with absolute or percent limits for the primary parameter and IN/OUT decision output for the secondary parameter. A list sweep function programs up to ten frequencies or test signal levels — and DC bias voltages when Option 001 is installed — for sequenced or single-point measurements. With Option 002 the instrument can also control the Keysight 42841A bias current source or the 42851A precision Q adapter for extended application coverage.
ValueTronics International, LLC stocks, tests, and ships precision LCR and impedance instruments from its 20,000 sq ft secure warehouse at 1675 Cambridge Drive, Elgin, Illinois. Every unit moves through our in-house inspection and performance verification process before it leaves the facility, and our team can package the instrument with the test fixtures, leads, and adapters needed for its intended application rather than asking the buyer to source those pieces separately. That single-source capability — instrument, fixtures, and condition documentation arriving together — is what separates a verified professional purchase from a marketplace listing.
Keysight Technologies inherits the test and measurement instrument lineage of Hewlett-Packard. HP spun off its test and measurement business as Agilent Technologies in 1999, and Agilent further separated its electronic measurement division as Keysight Technologies in 2014. Instruments originally introduced under the HP or Agilent brand — including precision LCR meters in the 428x family — are part of this continuous engineering and product-support lineage.
| Specification | Value |
|---|---|
| Measurement Functions | |
| Measurement parameters | |Z|, |Y|, L, C, R, G, D, Q, Rs, Rp, X, B, φ |
| Mathematical functions | Deviation and percent of deviation of measurement values from a programmable reference value |
| Equivalent measurement circuit | Parallel and series |
| Ranging | Auto and manual (hold/up/down) |
| Trigger | Internal, external, BUS (GPIB), and manual |
| Delay time | 0 to 60.000 s in 1 ms steps |
| Measurement terminals | Four-terminal pair |
| Test cable length | 0 m, 1 m, and 2 m selectable |
| Integration time | Short, medium, and long selectable |
| Averaging | 1 to 256, programmable |
| Test Signal | |
| Frequency | 75 kHz to 30 MHz, 100 Hz resolution |
| Frequency accuracy | ±0.01% |
| Signal modes | Normal and Constant |
| Voltage level (Normal) | 5 mVrms to 2 Vrms |
| Voltage level (Constant, ALC ON) | 10 mVrms to 1 Vrms |
| Current level (Normal) | 200 µArms to 20 mArms |
| Current level (Constant, ALC ON) | 100 µArms to 20 mArms |
| Display Range | |
| |Z|, R, X | 0.00001 Ω to 99.9999 MΩ |
| |Y|, G, B | 0.00001 µS to 99.9999 S |
| C | 0.00001 pF to 999.999 µF |
| L | 0.001 nH to 99.9999 H |
| D | 0.000001 to 9.99999 |
| Q | 0.01 to 99999.9 |
| θ | −180.000° to 180.000° |
| Δ | −999.999% to 999.999% |
| Correction Functions | |
| Zero open | Eliminates measurement errors due to parasitic stray admittance (C, G) of the test fixture |
| Zero short | Eliminates measurement errors due to parasitic residual impedances (L, R) of the test fixture |
| Load | Improves measurement accuracy using a working standard as reference |
| List Sweep | |
| List sweep points | Maximum of ten frequencies or test signal levels |
| Comparator Function | |
| Primary parameter sorting | Ten-bin sorting |
| Secondary parameter | IN/OUT decision output |
| Sorting modes | Sequential mode and Tolerance mode |
| Bin count | 0 to 999999 |
| Interface | |
| GPIB | IEEE-488.1 and 488.2 compliant; ASCII and 64-bit binary data format |
| GPIB buffer memory | Up to 128 measurements |
| Programming language | Test and Measurement Systems Language (TMSL) |
| GPIB interface functions | SH1, AH1, T5, L4, SR1, RL1, DC1, DT1, C0, E1 |
| Power Requirements | |
| Line voltage | 100, 120, 220 Vac ±10%, 240 Vac +5% −10% |
| Line frequency | 47 to 66 Hz |
| Power consumption | 200 VA max. |
| Operating Environment | |
| Temperature | 0 °C to 55 °C |
| Humidity | ≤ 95% R.H. at 40 °C |
| Physical | |
| Dimensions | 426 (W) x 177 (H) x 498 (D) mm |
| Weight | Approximately 16 kg (35.3 lb., standard) |
| Display | LCD dot-matrix display |
| Number of display digits | 6-digits, maximum display count 999999 |
| Supplemental Performance Characteristics | |
| Stability |Z|, |Y|, L, C, R (≤ 1 MHz) | < 0.01%/day |
| Stability |Z|, |Y|, L, C, R (30 MHz) | < 0.05%/day |
| Stability D (≤ 1 MHz) | < 0.0001/day |
| Stability D (30 MHz) | < 0.0005/day |
| Temperature coefficient |Z|, |Y|, L, C, R (≤ 1 MHz) | < 0.004%/°C |
| Temperature coefficient |Z|, |Y|, L, C, R (30 MHz) | < 0.05%/°C |
| Settling time (frequency) | < 50 msec. |
| Settling time (test signal level) | < 100 msec. |
| Settling time (measurement range) | < 50 msec./range shift |
| Measurement time (SHORT) | 30 ms |
| Measurement time (MEDIUM) | 65 ms |
| Measurement time (LONG) | 200 ms |
| GPIB data output time | Approx. 10 ms |
Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.
Model No
Keysight
Condition
Used
Manufacturer
Agilent
Frequency
30 MHz
1
Power amplifier/DC bias
2
Bias current interface
6
2 m/4 m cable length operation
201
HANDLER INTERFACE
202
HANDLER INTERFACE
301
Scanner interface
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