The SVR Series
SVR A basic 10V board supporting a monolithic Analog Devices AD587LN voltage reference
chip with a trim circuit for calibration as a transfer standard. Short term transfer accuracy: better than +/- .0005% absolute (+/- 5 ppm), guaranteed to remain longer term (6 months) within +/- 500 uV (+/- .005%) of absolute as rated 1. {5 ppm / ºC} $34.95
Short term transfer accuracy applies in the short term at the reported temperature and at the specified power supply voltage (15.0V for 10V SVR references) after of warm up period of 30 to 60 minutes, <10 ppm within 5 minutes.
The SVR requires an external (not supplied) single 15 VDC power supply, preferably using a linear regulator. With no load on the SVR board, the board draws on the order of 2 mA. A 15 VDC linear power supply rated at 80 milliamps or more is recommended. For relatively low accuracy applications (.01%), two 9V batteries in series can power the board at about 18 V.2
SVR bare printed circuit board with no components: $4.95
SVR (boards only) are now RoHS compliant, and can sell again to EU countries.
SVR Specifications:
Temperature Coefficient "L" grade: 5 ppm / ºC
Short term transfer accuracy: better than +/- .0005% absolute (+/- 5 ppm).
Short term transfer accuracy applies in the short term at the reported temperature and at the specified power supply voltage (15.0V for 10V SVR references) after of warm up period of 30 to 60 minutes, <10 ppm within 5 minutes.
All reference boards and boxes are calibrated to within +/- 10 uV absolute and guaranteed to remain longer term (6 months) within +/- 500 uV (+/- .005%) of absolute as rated.
Extra trim resistors are added to narrow the trim range for easier calibration. Calibration data is reported to 10 uV resolution (.0001%).
The AD587 series reference chips are rated at 15 ppm / 1,000 hours of operation. Very close inspection of most monolithic reference chip family specification sheets reveals a 1,000 hour rating generally ranging from 10 to 60 ppm / 1,000 hours.
Our Low Cost Voltage Transfer Project for Amateur Scientists, Electronics Hobbyists, and Schools, is Supported in Part by Analog Devices Incorporated. Please visit the Analog Devices website!
1 By maintaining a calibrated Fluke 732B primary laboratory standard in conjunction with our Agilent 3458A DMM we are able to offer NIST traceable references at affordable prices. Our 732B is under a Fluke calibration contract.
2 Suitable Power Supplies: Inexpensive linear "open frame" supplies can be used. For example, 15 VDC models rated at 0.4A, 0.8A, 1A, and 1.5A are generally available at surplus and auction sites. Please remember to add an AC power fuse when using open frame supplies.