HATS-LR Series LOW RESISTANCE TRANSFER STANDARD

HATS-LR Low Resistance Transfer Standard.
In order to perform calibrations with a high degree of accuracy, reference standards must be employed at every range or decade of the measuring or calibration instrumentation. 
Clearly, this can be difficult and costly since these standards must be highly stable and their precise values must be known with a high degree of certainty and sufficient resolution.
To minimize the cost and difficulty, more practical means of performing such calibrations is to use transfer standards.
If one has a single standard that is calibrated by a national laboratory, one can then compare the transfer standards to the certified standard by ratio techniques.

• Steps from 1 Ω to 100 kΩ

• Transfers from 0.1 Ω to 1 MΩ

• High transfer accuracy - to 1 ppm

The HATS-LR Series of transfer standards consist of 12 matched resistors, of value R, which may be connected in series or parallel combinations to produce any number of values such as R/10, R, and 10R, all with the same known deviation, thereby allowing progressive transfers to higher and lower decades. 
For example, the 10 k transfer standard may be used to transfer calibrations across 1 k, 10 k and 100 k.

Resistor Type: Wirewound, hermetically sealed, low inductance.
Step Size: 1 , 10 , 100 , 1 k, 10 k, or 100 k.
Accuracy:
Initial: ±15 ppm for 1 , 10 steps; 
           ±10 ppm for 100 through 100 k steps.
Long Term: ±15 ppm for 1 year;
                      ±30 ppm for 2 years; 
                     ±45 ppm for 5 years.
Transfer: ±(1 ppm + 0.1 μ) for 10:1 and 100:1 ratios for 1 , 100 , 1 k, 10 k, or 100 k steps;
             ±1 ppm for 10:1 and 100:1 ratios for 10 step.
(Transfer accuracies apply when HATS-LR-SB, HATS-LR-PC, or HATS-LR-SP fixtures are used)
Matching:
Accuracy: within 10 ppm for 1 , 10 steps;
              within 5 ppm for 100 through 100 k steps.
Temperature Coefficient: within 5 ppm/°C for 1 step;
                                   within 3 ppm/°C for ≥ 100 steps.
                                   within 5 ppm/°C for HATS-LR-10 only
Calibration Accuracy: ±10 ppm for 1 and 10 steps;
                             ±5 ppm for all others.
Temperature Coefficient:
±1 ppm/°C for HATS-LRTC-10 (lo TC version)
±10 ppm/°C for HATS-LR-1;
±3 ppm/°C for HATS-LR-10;
±1 ppm/°C for HATS-LR-100 through 100K.
Power Coefficient:
±0.1 ppm/mW per resistor for HATS-LR-1;
±0.15 ppm/mW per resistor for HATS-LR-10;
±0.02 ppm/mW per resistor for HATS-LRTC-10;
±0.05 ppm/mW per resistor for HATS-LR-100 through 100K.
Maximum Applied Input: 1500 V maximum or 1 W per resistor, or 5 W for entire unit, whichever applies. 1500 V peak between any terminal and case.
Dimensions: 31.2 cm W x 9.7 cm H x 11.4 cm D (12.3" x 3.8" x 4.5").
Weight: 2 kg (4.4 lb).
Calibration Conditions: Four-wire Kelvin measurements, low power, at 23°C, traceable to NIST. Initial calibration data supplied with instrument.
Leakage Resistance: Greater than 1 T from terminal to case.
Shorting Bars and Compensation Networks: For connecting resistors in parallel or series-parallel combinations.