DC VOLTAGE

Voltage Laboratory has developed high accuracy capability to support national voltage activities. The chart illustrates the traceability for voltage measurement in Malaysia.

The traceability of DC voltage standard to SI unit is realised by using Josephson Junction Voltage system in the range of 1 V, 1.018 V and 10 V with best uncertainty at 0.2 mV.

JJV Systems Zener Voltage Standard 732B Zener Voltage Standard 7001

RESISTANCE

Resistance laboratories provide the measurement traceability for resistance as well as development and maintenance of national physical standards for resistance. The laboratories provides calibration measurements with capability  from 1 m to 1 T. The National Standard of Resistance is a 1  and 10 k resistors kept in an oil bath at temperature of 23°C ± 0.001°C. The reference standard resistor is calibrated at BIPM on a regular schedule and disseminate to other resistors by using the automated DCC bridge at range of 1 m to 10 M. Resistance values below 1 achieved by using Direct Current Comparator Bridge with a Range Extender. The system has ratios up to 1000:1 with the relative uncertainty of 10-6. The resistance values from above 10 M are scaled up using a modified Wheatstone bridge by replacing Resistive arms with 2 DC Voltage. The resistance laboratories dissemination, capability and uncertainty are shown in following table and diagram respectively. 

        

DC Resistance

:
  • Low range - 1 m to 100 m

  • Medium range - 1  to 10 M

  • High range – 100 M to 1 T

1

Best Measurement Capability

:

    ±0.5 m/ to ± 585 m/

                                                            1   standard resistor

DC Current  Shunt

:
  • 1 A to 100 A

 

Best Measurement Capability 

:     ±   5 mA/A to ± 100 mA/A   

 

 

 

 

 

 

 

2

CAPACITANCE & INDUCTANCE

SERVICES PROVIDED :

 

The capacitance measurement services:

  • Low loss capacitor; fixed value
    1 pF - 1000 pF at 1 kHz, 1592 Hz
  • Dielectric capacitor (e.g. mica, polystyrene)

    1 µF - 100 µF at 1 kHz

  • Decade Capacitance

    100 pF to 1 µF

  • Capacitance meter

    1 pF to 1 µF

  • Dissipation Factor

    5X10-6 to 1X10-4

 

Inductance measurement services:

  • Calibration of self-inductance

    100 µH to 1 H

  • Decade Inductance

    100 µH to 10 H

  • Inductance meter

    100 µH to 10 H

In capacitance measurement, there are two types of national capacitance standards maintained; toroidal cross capacitor (1 pF) and fused-silica standard (1, 10, 100 pF). The 1 to 100 pF standard capacitors are used to calibrate the high precision capacitance bridge. Customer standards are calibrated by direct and substitute calibration method using a precision bridge.

i1
 

Inductance primary measurement is based on comparison bridge. The comparison procedure describes one inductor to be compared with another inductor within 10:1 range. The standard inductors are then used to calibrate the inductance meter (LCR) and customer standards are directly measurmetered by this meter.

i2 
 i3

TIME AND FREQUENCY

tf3NMIM’s Time and Frequency laboratory maintains two high performance and three standard performance Caesium (Cs) atomic reference frequency standards. One of the high performance Cs reference frequency standards is designated as Malaysian National Frequency Standards (MNFS), with accuracy of ± 5 × 10-13 s .

tf1

 With these standards and continuous All-in-View GPS time comparisons, where the data is contributed to Bureau Weights and Measures (BIPM) for the generation of the International Atomic Time (TAT) scale. NMIM is capable to provide traceability to the SI Unit of time interval for time and frequency measurement.

tf2

 Malaysian Standard Time (MST) is UTC (NMLS) + 8 Hours, due to the time zone selected which is the longitude of 1200 East. UTC (NMLS) is currently defined to be the epoch of the 1 pulse per second timing signal output at the rear panel of the Malaysian National Frequency Standards. NMIM steers the frequency of the standard to maintain UTC(NMLS) to be within approximately 1 ms of the Coordinated Universal Time (UTC).

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