Dielectric measurement below the microwave bands. Using the Keysight 16451B parallel plate fixture with an Agilent 4275A multi-frequency LCR meter, the Intelligent Electromagnetic Sensor Laboratories (iEMSL) measures dielectric constant (Dk) and dissipation factor of solid dielectrics from 10 kHz to 10 MHz, per ASTM D150, at room temperature.
Available now. The fixture is in the lab; we are accepting samples and scheduling work.
10 kHz – 10 MHz
Below the microwave bands
ASTM D150
Test method followed
Solid dielectrics
Returned to you
5 business days
Standard turnaround
Why the parallel plate fixture
A sheet of the material is clamped between two electrodes and permittivity is derived from the capacitance and loss of the resulting capacitor. That is the most direct dielectric measurement there is, and it is the only method at iEMSL that reaches below the megahertz, where no resonator or waveguide can help you. The next lowest method here, the coaxial probe, starts at 4 MHz.
It is the right method for insulation, cable and capacitor dielectrics, potting compounds, and any material whose data sheet quotes Dk at 100 kHz or 1 MHz. It is the wrong method above 10 MHz. Use WR-90 for X-band, the SPDR at 10 GHz, the FPOR for broadband low-loss work, and the DAK-TL2 probe for liquids and lossy materials.
Technical specifications
| Frequency range | 10 kHz – 10 MHz |
|---|---|
| Standard | ASTM D150 |
| Measured quantities | Dielectric constant (Dk) and dissipation factor |
| Sample thickness | Up to 10 mm |
| Sample diameter | 10 – 56 mm |
| Sample state | Solid dielectrics only |
| Temperature | Room temperature only |
| Instruments | Keysight 16451B parallel plate fixture with an Agilent 4275A multi-frequency LCR meter |
Sample requirements
The measurement is a capacitance measurement, so the geometry between the electrodes is the measurement. An air gap where an electrode should be touching reads as a lower permittivity, and a wedge-shaped sample reads as neither of its thicknesses.
- Diameter: 10 to 56 mm
- Thickness: up to 10 mm
- Faces: flat, smooth and parallel, so both electrodes make full contact
- State: solid only. Liquids, gels and pastes go to the DAK-TL2 probe
What to send us
- Your samples, meeting the diameter and thickness above
- The measured thickness of each sample, if you have it, since thickness enters the result directly
- A Safety Data Sheet for every material involved
- Expected Dk and dissipation factor, if you have an estimate
ASTM D150 testing pricing
$500 per sample
One flat rate per sample, from 10 kHz to 10 MHz. Standard turnaround 5 business days from the day your samples arrive, with rush service available.
Texas A&M researchers receive 50% off listed prices.
What you receive
- Dk and dissipation factor at each frequency you requested
- Raw data in CSV
- Technical Report on request (for extra charge)
- Your samples back. Nothing is disposed of at the lab
View our example measurements. See also: WR-90, SPDR, FPOR, DAK-TL2, all material characterization services.
Frequently Asked Questions
Why measure at 100 kHz when my circuit runs at 5 GHz?
You should not, and that is the point of having both. Permittivity is frequency dependent, so a Dk quoted at 100 kHz can be materially different from the same material at 10 GHz. Measure at the frequency your design operates at. The parallel plate exists for the designs that operate down here: insulation, cable, capacitor and potting materials, and for matching a supplier data sheet that quotes Dk at 100 kHz or 1 MHz.
Do I pay per frequency?
No. Parallel plate is $500 per sample, flat, from 10 kHz to 10 MHz. Unlike the resonator and waveguide methods, one setup covers the whole range, so there is nothing to quote band by band.
What sample size do you need?
A solid disc or coupon 10 to 56 mm across and up to 10 mm thick, with flat, smooth, parallel faces. Thickness enters the result directly, so a wedge-shaped sample cannot give a clean answer. Send the measured thickness with the sample if you have it.
Can you measure a liquid or a powder?
Not with this fixture. It measures solid dielectrics clamped between electrodes. Liquids, gels and slurries go to the DAK-TL2 coaxial probe, which covers 4 MHz to 67 GHz. Tell us what the material is and we will route it to the method that fits.
Can you measure at elevated temperature?
Not with this method. The parallel plate service is offered at room temperature only. The SPDR is the iEMSL method offered up to 100 °C, at a single frequency of 10 GHz.
Can you handle ITAR-controlled or export-controlled work?
Yes. iEMSL accepts ITAR-controlled projects under a Technology Control Plan, administered with the Texas A&M export control office. Tell us your control requirements when you request a quote, before shipping any samples.
Need Dk below the microwave bands?
Tell us the material and the frequencies that matter, and we will quote the measurement you need.