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 reference. 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
Since first offered in 2004, many hundreds of SVR boards are now in use world wide.
SVR boards can ship in the US by USPS First Class Mail for $2.03 or Priority Mail for $4.80. International buyers please contact us or check USPS prices for 5 ounces (oz), SVR shipping box is 7"x 5" x 4".
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: $5.95
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%).
JANUARY 2010: Our Fluke 732B primary reference standard (used to calibrate our Agilent 3458A 8.5 digit DMM) has been in the Fluke calibration system for five years. Since then it moves on average -0.2 ppm per year. Our last cal. date was 11/2008. We delayed the annual calibration this year for financial concerns (over $500 / year). However, we do run a fit of the cal data tabulated per month based on the now predicable change with time. These numbers are well below the specification for our reference products.
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.
All checks and money orders should be made payable to "GELLER". Please see our ordering page for more information.
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 2005 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. Remember to add an AC power fuse when using open frame supplies and for those less experienced, please observe standard line voltage safety practices (e.g. cover exposed AC line connections).
COPYRIGHT © 2005 JOSEPH M. GELLER