10V .001% Reference Voltage Standard .4ppm/C int batteries + included ext supply

Description

Feature summary:
*Operation from internal 9V batteries or included external 24VDC power supply
* Output terminals are high quality gold plated 5-way binding posts
*Gold plated circuit board
* Temperature compensation circuitry provides 60
º
F to 90
º
F (16C- 32C) TC of < +- 2uV/F (0.4ppm/C) max (Box Method)
*Easily accessible current limited battery voltage test points
*All Temperature sensitive components (LT1021, etc) are located inside the enclosure to make the VRef10-001 r9 insensitive to ambient air currents
This small (3" x 3"), portable, precision voltage reference can be used to check the calibration of your DVM or DMM. The VRef10-001 r9 features a 10.00000V output, and is conservatively rated to be accurate within 0.001% for a minimum of 8 months. The circuit is based on the Linear Technology LT1021BCN8-10 which uses buried Zener technology resulting in excellent long term stability. Here is a link to the LT1021 datasheet:
https://www.analog.com/media/en/technical-documentation/data-sheets/1021fc.pdf
The VREF10-001 r9 can either be powered by the 2 included RayOVac Alkaline 9V batteries or the included
UL approved, linear, regulated, 120VAC/60Hz input, 24VDC output
power supply.  When powered by the batteries the unit is completely self contained and easily transported. Current drain is less than 5mA so the batteries will last many 10's of hours. Both the battery and 24V external inputs are reverse polarity protected and can withstand up to +/-40V without damage.
Buried Zener References become more stable the longer they are powered-up.  Operation with the included external
power supply
allows the VREF10-001 r9 to be continuously powered without draining the batteries.  As shown in the listing photo a lit red LED indicates battery operation and a lit orange LED indicates external power.  The switchover from batteries to external supply (or vice -versa) is virtually instantaneous and when both are present priority is given to the external supply.
An on-board on/off switch allows the removal of power from the VRef10-001 r9 even if the external supply is connected.
Temperature compensation circuitry lowers the VREF10-001 r9 temperature coefficient to less than +/- 0.4ppm/C over the range of  60ºF to 90ºF (16C to 32C ).  The temperature stability is verified by using our thermal chamber to slowly change the temperature from 60ºF to 90ºF over a period of 10 hours and measuring the Reference output every 0.1ºF. Please refer to the listing photo that compares an out-of-the box LT1021 with the dramatic improvement in temperature stability due to the included temperature compensation circuitry.
After the unit is assembled, it is powered up for a minimum of 2000 hours to "age" the reference and confirm its long term stability. After aging, a trim pot is carefully adjusted so that the output voltage is within 5uv of 10.000000V as measured by our calibrated, 8.5 digit Keysight 3458A DMM. (Keysight Certificate of Calibration WO-00730471, valid through March 8, 2025). The ambient temperature is recorded and unless specified otherwise will be in the range 68 to 70 degrees F. We can perform calibration at other temperatures- please inquire for feasibility and pricing.
For maximum accuracy it is recommended that the reference be powered-up at least 1 hour before use and also operated as close as possible to the calibration temperature.
Recalibration is free for the first two years after purchase- just mail it back to us and only pay for return shipping. After two years the calibration charge is .00 plus shipping.