Electrical Standards Section

Overview

Overview

The Electrical Standards Section (ESS) maintains reference standards for the electrical quantities of voltage, current and resistance. For frequency and time interval, it uses the Cesium Beam Primary Frequency Standard with international traceability to the Coordinated Universal Time (UTC) through Multi-frequency Global Navigation Satellite System (GNSS) Time and Frequency Transfer.

                                                                                              

The ESS also operates a photometry laboratory that maintains reference standards for luminous intensity.

                                                 

The ESS maintains the following Basic Electrical Quantities:

  • Voltage
  • Current
  • Resistance
  • Time/Frequency

DC Voltage

  • maintained from the mean value of a bank of electronic standard cells
  • traceability obtained from NMI’s abroad (typically Australia, Singapore) to an uncertainty of 0.05 to 0.08 ppm
  • cells in the bank are regularly intercompared to monitor stability of individual cells
  • used to calibrate customer standards (typical calibration uncertainty offered to customers: 0.3 ppm to 0.7 ppm
  • calibration process fully automated (using home-grown talent, expertise and technology)

 

Resistance

  • maintained with a set of Standard Resistors (values from 1 mW to 1 MW)
  • traceability obtained from NMI’s abroad (typically Australia, Korea) to an uncertainty < 1 ppm
  • measurements performed in temperature controlled oil bath with a stability and uniformity of ± 0.005°C; resistance measurements very dependent on temperature (typical temperature sensitivity 2 to 8 ppm/°C

 

For calibration of resistance standards from 100 mW to 1 MW resistance range:

  • Direct Current Comparator Bridge
  • Calibration is computer-aided

Calibration and measurement supported by:

  • technical procedures and work instructions
  • Certificate of Calibration
  • ISO 17025 compliant

 

 

International Measurement Intercomparisons

 

Area / Quantity Instrument / Artefact Date Intercomparison details
Ac-dc voltage transfer Fluke 5500A (voltage mode) May-96 Bilateral (NML, Australia now NMIA)
Ac-dc voltage transfer Fluke 540B Thermal Transfer Standard Aug-96 Bilateral (NML, Australia now NMIA)
Dc Resistance Standard resistors Dec-96 Bilateral (LCIE, France)
 (1 W, 10 kW and 1 MW)
Ac-dc current transfer Fluke 540B with external current shunts Apr-97 Bilateral (NML, Australia now NMIA)
Ac-dc current transfer Fluke 5500A (current mode) Aug-97 Bilateral (NML, Australia now NMIA)
Dc Resistance Standard resistors Oct-97 Bilateral (NML, Australia now NMIA)
 (10 W, 100 W, 10 kW and 1 MW)
Ac-dc voltage transfer Fluke 540B Nov-97 APMP
(with 10V & 100V test network)
Dc Resistance Standard resistors Apr-98 Bilateral (NML, Australia now NMIA)
 (1 kW, 10 kW, 100 kW and 1 MW)
RF Power HP 878478 Thermistor mount Feb-00 Bilateral (NML, Australia now NMIA)
Ac-dc voltage transfer Fluke 540B Thermal Transfer Standard May-01 Bilateral (NML, Australia now NMIA)
Ac-dc voltage transfer 3V Single-Junction Thermal Transfer Standard Aug-02 APMP K6
GPS Receiver Delay GPS Receiver Jul-06 APMP

 

Quality System

 

Calibration and measurement work supported by:
 
  • technical procedures and work instructions
  • Certificate of Calibration ISO 17025 compliant

Traceability

Traceability

Electrical

Services

Measurement Capabilities

  Table 1.1: Measurement Capabilities A
Calibration or Measurement Service Measurand Level or range Best Measurement Uncertainty
(95% confidence level, k=2)
Quantity Instrument or Artifact Minimum value Maximum value Units value Units
Dc current sources: Dc current sources/calibrators 0.0001 0.0001 A 2.1 mA/A
(0.0001 A to 1 A) 0.001 0.001 A 2.1 mA/A
0.01 0.01 A 11 mA/A
0.1 0.1 A 11 mA/A
1 1 A 11 mA/A
Dc Resistance Standard Resistors 1 1 W 0.31 mW/W
(1 W to 1 MW) Dc current sources/calibrators 10 10 W 0.52 mW/W
Dc current sources: 100 100 W 0.52 mW/W
(0.0001 A to 1 A) 1000 1000 W 0.52 mW/W
10000 10000 W 0.52 mW/W
100000 100000 W 1 mW/W
1000000 1000000 W 1 mW/W
Frequency Oscillator Timebase 10 10 MHz 1 part in 1010 ---
    Table 1.2: Measurement Capabilities B
Calibration or Measurement Service Measurand Level or range Best Measurement Uncertainty
(95% confidence level, k=2)
Quantity Instrument or Artifact Minimum value Maximum value Units value Units
Dc current sources: Dc current sources/calibrators 0.0001 0.0001 A 2.1 mA/A
(0.0001 A to 1 A) 0.001 0.001 A 2.1 mA/A
0.01 0.01 A 11 mA/A
0.1 0.1 A 11 mA/A
1 1 A 11 mA/A
Dc Resistance Standard Resistors 1 1 W 0.31 mW/W
(1 W to 1 MW) Dc current sources/calibrators 10 10 W 0.52 mW/W
Dc current sources: 100 100 W 0.52 mW/W
(0.0001 A to 1 A) 1000 1000 W 0.52 mW/W
10000 10000 W 0.52 mW/W
100000 100000 W 1 mW/W
1000000 1000000 W 1 mW/W
Frequency Oscillator Timebase 10 10 MHz 1 part in 1010 ---
  Table 1.3: Measurement Capabilities C
Calibration or Measurement Service Measurand Level or range Best Measurement Uncertainty
(95% confidence level, k=2)
Quantity Instrument or Artifact Minimum value Maximum value Units value Units
Dc current sources: Dc current sources/calibrators 0.0001 0.0001 A 2.1 mA/A
(0.0001 A to 1 A) 0.001 0.001 A 2.1 mA/A
0.01 0.01 A 11 mA/A
0.1 0.1 A 11 mA/A
1 1 A 11 mA/A
Dc Resistance Standard Resistors 1 1 W 0.31 mW/W
(1 W to 1 MW) Dc current sources/calibrators 10 10 W 0.52 mW/W
Dc current sources: 100 100 W 0.52 mW/W
(0.0001 A to 1 A) 1000 1000 W 0.52 mW/W
10000 10000 W 0.52 mW/W
100000 100000 W 1 mW/W
1000000 1000000 W 1 mW/W
Frequency Oscillator Timebase 10 10 MHz 1 part in 1010 ---
    Table 1.4: International Measurement Intercomparisons
Area / Quantity Instrument / Artefact Date Intercomparison details
Ac-dc voltage transfer Fluke 5500A (voltage mode) May-96 Bilateral (NML, Australia now NMIA)
Ac-dc voltage transfer Fluke 540B Thermal Transfer Standard Aug-96 Bilateral (NML, Australia now NMIA)
Dc Resistance Standard resistors Dec-96 Bilateral (LCIE, France)
 (1 W, 10 kW and 1 MW)
Ac-dc current transfer Fluke 540B with external current shunts Apr-97 Bilateral (NML, Australia now NMIA)
Ac-dc current transfer Fluke 5500A (current mode) Aug-97 Bilateral (NML, Australia now NMIA)
Dc Resistance Standard resistors Oct-97 Bilateral (NML, Australia now NMIA)
 (10 W, 100 W, 10 kW and 1 MW)
Ac-dc voltage transfer Fluke 540B Nov-97 APMP
(with 10V & 100V test network)
Dc Resistance Standard resistors Apr-98 Bilateral (NML, Australia now NMIA)
 (1 kW, 10 kW, 100 kW and 1 MW)
RF Power HP 878478 Thermistor mount Feb-00 Bilateral (NML, Australia now NMIA)
Ac-dc voltage transfer Fluke 540B Thermal Transfer Standard May-01 Bilateral (NML, Australia now NMIA)
Ac-dc voltage transfer 3V Single-Junction Thermal Transfer Standard Aug-02 APMP K6
GPS Receiver Delay GPS Receiver Jul-06 APMP
Dc Resistance Standard resistor (100 W) Jan-07 Bilateral (NIMT, Thailand)

Accreditation

The Electrical Standards Section of the National Metrology Laboratory of the Philippines is competent under the terms of ISO/IEC 17O25:2OO5 to carry out calibration of electrical standards.

ilac mra dakks

Scope of Accreditation

electrical scope

 Download Accreditation Certificate and Annexes