Products Under Development

Photonic Thermal voltage Converter System

Patent Pending: U.S. Application No. 64/187,908

Diagram of the photonic thermal voltage converter: a readout unit with a laser, a dc reference, and detectors and a processor connects through one umbilical to a sensor head. Inside the head, a reference fiber sensor and a sensing fiber sensor each sit in a bifilar heater. The dc reference drives the reference heater, and the ac or dc voltage under test drives the sensing heater through a Type N input.

An optical readout replaces the electrical connection between the source under test and the measuring instrument, removing leakage-current paths and ground loops. Fiber sensors in a thermally matched head are read with laser light, resolving ac-dc differences below 0.1 µV/V with about one second averaging. The sensor head has a Type-N input and fits existing ac-dc transfer setups with the addition of the readout unit.

PTVCs are under development for:

  • 2 mV to 1000 V, 10 Hz to 1 MHz
  • 0.5 V to 3 V, 10 Hz to 100 MHz
  • 50 Ω input, 0 dBm to +20 dBm, 10 Hz to 2 GHz

AC-dc Difference Step Kit – in-situ admittance correction kit

Diagram of the ac-dc difference step kit: an ac-dc source feeds a compact step tee. A 50 Ω standard and a high-impedance standard plug directly onto its two arms through step adapters that add known resistance and capacitance steps. The standards’ dc outputs go to the ac-dc software, whose plot shows the uncorrected ac-dc error rising with frequency from 10 kHz to 100 MHz while the corrected error stays at zero.

Ac-dc difference measurements assume that the standards being compared have similar input admittances. When they differ, as when a 50 Ω standard is compared with a high-impedance one, the resulting error is usually not measured. Labs either avoid the comparison or widen their uncertainties to cover it.

Cular Technologies has developed a semi-automated kit and procedure that measures this error in situ and corrects for it. Labs can then compare dissimilar standards directly, with a measured correction in place of an estimated allowance, which lowers the stated uncertainty.

The kit supports voltage scaling and comparisons between 50 Ω and high-input-impedance standards. Each kit includes:

  • STK-01: Step tee
  • STK-02: Step adapter pair
  • STK-03: TA-50
  • STK-04: Cartridge set
  • STK-05: SNS1k pair
  • STK-06: Emulators
  • STK-08: ACDC-SW
  • STK-09: Case, SMA/N torque wrenches, cables, ferrites
  • AC-DC Software: model, fit, planner, sequencers, simulators
  • Full documentation

AC-dc Difference Measurement Software

Screenshot of the Cular Technologies AC-DC Measurement System software showing the Results page. A table lists ac-dc differences with expanded uncertainties at 2 V from 20 Hz to 1 MHz. Below it, a plot shows the ac-dc difference against frequency with uncertainty bars, next to the GUM uncertainty budget for the selected point. Cards beneath the screenshot highlight automated runs, GUM uncertainty and SQL records.

Ac-dc difference measurement software designed to support ISO/IEC 17025 accreditation, with complete, traceable records of every measurement. Features include:

  • Automatic storage of all measurement data, calculations, corrections and bench setup in an SQL database
  • One database per system, or one shared database across multiple measurement systems
  • Data analysis and calibration certificate generation
  • Support for commonly used instruments, with new instruments easy to add
  • Management of standards and their corrections
  • Automatic correction for input-impedance mismatch between standards (see the ac-dc difference step kit)
  • Customizable to your laboratory’s procedures

For information on these products, contact us:

stefan@culartechnologies.com