NSCL maintains the following standards as the reference measurement standards of DC voltage, DC current, resistance and capacitance for Syria and for the dissemination of the related units:
- Two Fluke 732A as the reference measurement standards of DC voltage. The back to back method, using a digital voltmeter, is used to perform measurements.
- A current source serially connected to a set of Yokogawa 2792 resistors as the reference measurement standard of DC current, where a reference digital multimeter (Fluke 8508A) is used to measure the dropped voltage.
- A set of five double-wall standard resistors Yokogawa 2781 as the reference measurement standard of resistance, where a current comparator resistance bridge (Guildline 9975) is used to perform measurements.
- A set of four-dry nitrogen capacitors GR 1404A and GR 1404B as the reference measurement standard of capacitance, where a capacitance measuring assembly bridge (GR 1620-AP) is used to perform measurements.
Measured quantity/Calibrated item | Range | Expanded uncertainty (K=2) |
DC voltage sources | ||
Standard cells | 1.018 V | 1.9 ppm |
Solid state voltage standards | 1 V, 1.018 V, 10 V | (1.3 to 2.1) ppm |
DC voltage calibrators | 1 mV to 1000 V | (2.4 to 830) ppm |
DC voltage meters | ||
Standard DC voltage meters | 100 mV to 1000 V | (2.8 to 17) ppm |
DC voltage meters | 1 mV to 100 mV | (17 to 830) ppm |
DC current | ||
Sources | 100 μA to 100 A | (16 to 300) ppm |
Measuring instruments | 100 μA to 100 A | (14 to 300) ppm |
DC resistance | ||
Fixed standard resistors and resistance boxes | 10 mΩ to 10 MΩ | (8 to 30) ppm |
Current shunts | 1 mΩ to 10 mΩ | (22 to 300) ppm |
Capacitance | ||
Fixed capacitors and capacitance boxes | 100 pF to 10 μF at Freq 1 kHz | (20 to 380) ppm |
Capacitance bridges & capacitance meters | 1 pF to 10 μF at Freq 1 kHz | (110 to 380) ppm |
Dissipation factors | > 1 ∙ 10-6 to 1 at Freq 1 kHz | 1000 ppm . tan δ + 50 ppm |