GENERAL

Precision resistance standards designed for use up to 10 kHz
Available for values from 1 mΩ – 10 MΩ
Bnc option available (add -bnc to end of part number)
Contact IET for custom resistance values

Very stable <20 ppm/year for most values at ac and dc
ISO-17025 accredited calibration at dc and 1 kHz Included
< 25 ppm difference between dc / 1 kHz for resistances ≤ 100 kΩ
Excellent temperature coefficient, as low as 1 ppm/°C

DESCRIPTION

Most precision standard resistors are sealed. Where sealed resistors are more stable, they have a poor frequency response.
IET has designed and manufactured our SRAC Series which has excellent ac frequency response while maintaining long term stability of less than 20 ppm.

Calibration: Unlike most resistors, where the calibration value is only available at dc, IET Labs provides an ISO-17025 accredited calibration of these resistors at dc and at 1 kHz. Sweep calibrations and other frequencies are available for a premium.

Configuration: Units come standard with 4 gold plated low thermal emf binding posts, plus ground for use in both 2, 3 or 4-Wire kelvin applications. For a small premium we can make this in any configuration you require including bnc.

Decade Box: If you are looking for a Decade Resistor with very strong ac performance consider our 1433 Series

Frequency response lower resistance, for example, 1 Ω will have a much better frequency response than higher resistance, for example, 10 MΩ

Because calibration uncertainties are much better at dc than ac, IET recommends that for resistance values below 1 MΩ it is recommended to use the dc value for the ac value at 1 kHz. For resistance values of 1 MΩ and 10 MΩ it is recommended to use the ac value.

The frequency response for SRAC values of 100 kΩ and lower is based upon the formula below;

SPECIFICATION

Model SRac-	Nominal (Ω)	Initial adjustment to nominal (ppm)	Stability 1 year (ppm)	Tempco (ppm/°C)	Resistor Type	Calibration uncertainty dc (ppm) (typical)	dc to ac change at 1 kHz (ppm) (Typical)	Max Power (W)	Max Voltage (V)	Max Current (A)	Terminals
0.001	0.001	200	50	20	Manganin strip	200	25	0.2	0.015	14	4 bp’s + gnd
0.01	0.01	200	50	20	Manganin wire	100		0.6	0.15	4.5
0.1	0.1	100	20	1	Foil	60		0.3	0.17	1.7
1	1			1		10		0.3	0.54	0.54
10	10			2		5		0.6	2.45	0.245
100	100			1		5			24.5	0.024
1K	1 k			1		5			77.5	7.7 mA
10K	10 k			1		2			245	2.5 mA
100K	100 k			1		2			300	2 mA
1M	1 M			5	Wirewound	5	250	0.5	700	0.7 mA
10M	10 M			15	Film	10	2500	0.1	1000	0.1 mA

DATASHEET AND MANUAL

Data Sheet: This document explains the features, options, Specifications and option models for this item.
Product Manual: Specifications and option models for this item. This document contains the technical product manual and guidelines.

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