PRS-300 Precision Programmable Resistance Decade

  • Resistance Range: 0.1 Ω to 20 MΩ
  • Precision Lab Grade Accuracy 70 ppm + 1 mΩ
  • Resolution: 1 μΩ ( 0.000 001 Ω) or 6 digits
  • To further improve accuracy to <20 ppm, for no additional cost, see the PRS-DMM
  • Programmable resistor with USB interface and Labview drivers
  • 5 year warranty
  • Virtually no maintenance cost, very simple to calibrate
  • High reliability relays, rated for 100 Million Switches
  • With Built-in PT-100 and PT-1000 Tables, RTD values can be input in both °C, °F or Ω
  • Built-in EIA "preferred value" resistance tables
  • No zero or switch resistance
  • PRS Selection Guide
Priced at
The PRS-300 dramatically improves the most important aspects of the older manual resistance decades. It introduces an advanced algorithm to create a easy to use programmable resistor with 30% improved accuracy and 1000 times better resolution than traditional laboratory decade boxes and RTD Simulators.

The PRS-300 was designed with the right mix of features for to be efficient for both manual and automated application in both laboratory and production environments. With its wide range the PRS-300 was designed to replace multiple decade boxes and reduce test time.

With its industry leading 5 year warranty all aspects of the PRS-300 focus on reliability, reduced ownership costs and simplicity out of the box.

The simple user interface makes PRS-300 well suited for high accuracy requirements for both manual and automated applications such as RTD simulation, DMM calibration, circuit trimming, and load testing.

PRS-300 Advantages:

Further Improve On Accuracy to <15 ppm
Additionally, if you own an 8.5 digit DMM like Fluke 8508A or the Keysight 3458A, for no additional cost, the PRS-300 can be used as part of the PRS-DMM system which will further improve on the accuracy of the unit to <15 ppm.

Interface and Drivers
Operation is both local using a convenient numeric keypad and up/down arrow keys or remote control with standard USB and optional Ethernet, and IEEE-488 interfaces.

Highest Quality Components
The programmable resistance box employs, high-quality gold-plated tellurium-copper five-way binding posts serve to minimize the thermal emf effects, which would produce errors in dc resistance measurements. Resistors are custom Z-foil and low inductance wirewound for low TC and excellent stability.

RTD Calibration
Built-in tables for PT100 and PT1000 RTDs and direct resistance substitution makes the PRS-300 ideal for for RTD (Resistance Temperature Detector) simulation. User defined tables can also be created for use with other RTDs. The operator can enter temperature directly and the correct resistance will automatically be programmed.

Resistor Carousel
Built-in EIA "preferred value" resistance tables of 1% (E96), 5% (E24), 10% (E12) increments or user specified increment allows the PRS-300 to be used as a resistor carousel.

AC Performance
The PRS-300 programmable resistance box is a precision resistance source with excellent characteristics of stability, temperature coefficient, and power coefficient. The use of low inductance wirewound and Z-foil resistors allows the PRS-300 to be used in ac applications with minimal resistance change below 1 kHz.

No Zero Resistance
The PRS Series programmable resistance box employs very low resistance, low thermal emf relays with gold-clad silver-alloy contacts. A special design keeps contact resistance to a minimum. The gold plating keeps the silver contacts from becoming tarnished when unused, or when only low currents are passed through them. This is most often the case when only minute test currents are drawn by digital multimeters and other test instruments. Contact resistance remains low and repeatable through the use of multiple contacts.

USB Driver for Windows 7 and Windows 10
For USB interface:

Unzip the file and follow instructions to install. The USB interface uses an FTDI Driver.

Optional Rack Mounting
The PRS Series programmable resistance box may be rack mounted to serve as components in measurement and control systems.

Watch a video about the
PRS-300 Precision Programmable Resistance Decade


(See datasheet for full specifications)

User interface:Numeric keypad to enter resistance value with digital display
Accuracy: ±(70 ppm + 1 mΩ) 4 Terminal
Minimum setting: 0.1 Ω
Resolution: 1 μΩ or 6 digits
Range: 0.1 Ω- 20 MΩ
Stability: ±50 ppm/year
Thermal emf: < 15 μV
Maximum Load: 2 A, 200 V (peak), 0.5 W whichever applies first
Resistors: Precision wire-wound and metal foil
RTD Tables:
3 RTD tables can be entered into memory to allow user selection of temperature and the correct value of resistance will automatically be programmed. PT100 and PT1000 tables are pre-programmed into memory.
Adjustment: Automatic adjustment procedure utilizing a high precision DMM eliminates the requirement for manual trimming of resistors.
4 low-emf, gold-plated, tellurium-copper 5-way binding posts are used for HI and LO terminal pairs for CURRENT and SENSE. GND binding post is connected to the case and to earth ground.
Switching time: Power requirements: 90 - 264 Vac , 47 - 63 Hz., 30 Watts Max.
Bench model: 43 cm W x 8.9 cm H x 33 cm D (17" x 3.5" x 13") in front of panel: 3.8 cm (1.5").
Bench model: 4.0 kg (9 lb); Rack model: 4.5 kg (10 lb);
weight specifications are nominal.
Remote Control:
USB: USB interface standard on rear panel
Remote Control Options:
GPIB standard 24 pin connector, conforms to IEEE- 488.2; SCPI 1994.0 command set; Hardware or software configurable addressing range of 1 to 30.
IEEE 802.3 compliant, Speeds 10 BaseT (10 Mb/s) and 100 BaseT (100 Mb/s), IP Address Static or DHCP, Factory setting static