DMM Check Calibrator Tester AC/DC Voltage & Current Freq Reference Standard, US $79.00 – Picture 0

DMM Check Calibrator Tester AC/DC Voltage & Current Freq Reference Standard, US $79.00 – Picture 1

DMM Check Calibrator Tester AC/DC Voltage & Current Freq Reference Standard, US $79.00 – Picture 2

DMM Check Calibrator Tester AC/DC Voltage & Current Freq Reference Standard, US $79.00 – Picture 3

Dmm Check Calibrator Tester Ac/dc Voltage & Current Freq Reference Standard

US $79.00

Battle Ground, Washington, United States
Mar 2nd

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The DMMCheck Plus is a battery powered device that checks seven important functions on a DMM: AC and DC Voltage, AC and DC current, Resistance, Frequency, and Duty Cycle. It you have a DVM or DMM that has questionable accuracy, the DMMCheck Plus can give you the confidence you need before relying on your test equipment. Provided on the small (3"W x 3"L) circuit board are the following circuits: Resistance : Four 0.1%, 10ppm/C precision resistors are included: 100?, 1.00K?, 10.00K?, and 100.0K? DC voltage : 5V, ± 0.007% voltage reference DC current : 1mA, ±0.1% current source AC voltage : 5V RMS, bipolar (+5V, -5V) square wave, ±0.1% voltage source AC current : 1mA RMS, ±0.2% current source Frequency : 100Hz, ±0.02% signal source Duty Cycle : 100Hz, 5V RMS, signal source has 50% ± 0.05% duty cycle The above specifications are guaranteed for a minimum of 6 months. An external power supply is not needed; The included 9V battery makes the unit self-contained, easily transported, and avoids ground loops. An on-board on/off switch allows you to maximize battery life when not in use. Reverse polarity protection is included, so even if the battery is placed in the holder backwards no damage will result. When the AC/DC slide switch is in the AC position, AC voltage and AC current reference signals are present at the “V” and “I” terminals. When in the DC position, DC voltage and DC current reference signals are produced. A high brightness, low current LED clearly indicates when the DMMCheck Plus is powered-up. You can use the DMMCheck Plus as-is or alternatively take advantage of the holes that are in the corners of the circuit board to mount the assembly in an enclosure. 5VDC VOLTAGE REFERENCE: The 5V reference voltage is based on the Linear Technology LT1021BCN5-8 buried Zener precision reference IC. After the DMMCheck Plus is assembled, it is powered up with a 9V power supply for a minimum of 250 hours to "age" the reference and improve its long term stability. After aging, the trim potentiometer is carefully adjusted for a reference output of 5.0000V as measured by our calibrated 8.5 digit HP 3458A DMM that has an accuracy of 0.0008%. (Agilent Technologies, Loveland Standards and Calibration Labs, Certificate of Calibration 1-6455731337-1, valid through January 14, 2016). Accidental movement of the trimpot adjustment is prevented by the application of a small amount of acrylic enamel. The ambient temperature is also recorded. (typically 68F). The circuit board was designed to minimize the effects of mechanical stress on the voltage reference IC. Specifically, the reference is placed on the edge of the circuit board and 2 adjacent board slots prevent stresses in the board from reaching the reference IC which could otherwise cause the output voltage to shift. Recalibration of the voltage reference is free for the first two years after purchase - just send it back to us and include $4.00 in stamps for return shipping within USA. After two years the charge is $5.00 plus shipping. Please contact us for shipping charges to destinations outside the USA. PRECISION RESISTORS: 100?, 1K?, 10K?, and 100K? 0.1%, 10ppm/C resistors (Vishay type PTF56), connected in series are available to check the resistance function of your DMM. Depending on how you connect your meter leads many different resistance values are available. The resistors are guaranteed accurate within 0.1% of their stated values, but the actual value obtained with a 4-wire (Kelvin) measurement using our HP 3458A (.001% accuracy on OHMS) is provided on the included 'Measured Values' sheet shown in the second listing photo. 1.000mA DC CURRENT SOURCE: A 0.1% accurate active 1mA DC current source is provided to check the DC current measurement accuracy of your DMM. The compliance voltage is approximately 500mV which accommodates load resistances from 0 Ohms to 500Ohms. To use this feature, set your DMM to measure DC current and connect the test leads to the provided current source terminals. The DC current sourced by DMMCheck is guaranteed to be within 0.999mA and 1.001mA, with the actual value, as measured by our calibrated 3458A, indicated on the included as-measured sheet. The only DMM's that we are aware of that are NOT compatible with DMMCheck Plus is the Fluke 116 which has a burden resistance of 3KOhms when measuring DC current and the Uni-Trend UT61E which has a burden resistance of about 1KOhms 5VAC RMS VOLTAGE REFERENCE: A 0.1% accurate, 5.00VAC RMS, square wave 100Hz voltage source is used to check the AC voltage accuracy of your DMM. The signal is true AC (bi-polar), not pulsed DC. It can also be used to check the compensation of oscilloscope probes. Note that true RMS-reading DMM's such as Fluke 87, 287, 289 or Extech 540, 570 will agree with the AC voltage shown on the 'Measured Values' sheet shown in the picture. Less expensive DMM's are average responding and are calibrated for sine waves not square waves. The result is that average responding meters read 1.11 times higher than true RMS meters when measuring a square wave such as the one produced by DMMCheck Plus. The bottom line is that an average responding meter, when measuring a 5.00V RMS square wave, will display 5.55V and a RMS responding meter will display 5.00V. 1.00mA AC RMS CURRENT SOURCE: A 0.5% accurate, 1.00mA AC RMS, 100Hz current source is used to check the AC current accuracy of your DMM. 100Hz, 50% DUTY CYCLE SIGNAL SOURCE: A100Hz, 5VAC voltage reference is generated by microcontroller firmware running off a 4MHz quartz crystal controlled clock. The firmware can be modified to generate other frequencies and duty cycles – please inquire with your specific needs.The frequency and duty cycle are measured by our Agilent 53220A frequency counter using a 10MHz GPS disciplined oscillator as an extremely accurate external timebase. Dual-frequency option: You can have two frequencies programmed into your DMMCheck Plus instead of just the standard 100Hz signal. Specify any two frequencies between 25Hz and 20KHz when you place your order. The list, below, shows how close the generated frequencies will be to what you specify, with the actual frequencies and duty cycles recorded on the included "Measured Values" table as measured by our calibrated Agilent 53220A frequency counter. This option costs an additional $10.00- please contact us at the time of ordering to specify your choice of frequencies and also to arrange payment via PayPal. 25Hz - 999Hz 0.1% 1KHz - 9.99KHz 1% 10KHz - 20KHz 2% Here is how you switch between the two frequencies: If the AC/DC switch is in the AC position on power-up or after switching from DC to AC the first time with the power on, the lower of the two frequencies is generated. While keeping the unit powered-on, slide the AC/DC switch to the DC position and then back to AC- the higher of the two frequencies is then generated. Subsequent switching from AC to DC and back to AC will select the other frequency. AC/DC voltage output, output resistance : 25Ohms, typical* Current drain: 5 mA typical Powered by included Alkaline 9V battery *The DMMCheck Plus is calibrated with a 10M? load connected to the voltage output terminals when measuring DC; 10M? is the typical input resistance of most DMM’s when measuring DC Volts. A 1M? load is used for AC Volts. Please specify if you require a different load resistance. Picture #3 shows a 4-wire (Kelvin) measurement of a DMMCheck Plus 1K precision resistor with our calibrated 3458A DMM (3458A and Kelvin leads not included) Picture #4 shows the 100Hz oscillator frequency being measure by our Agilent 53220A Frequency Counter. The "Ext Ref" in the upper right corner of the display indicates an external timebase is being used. We use an extremely accurate Spectracom Secure Sync 10MHz GPS disciplined oscillator as the external time base (53220A and cable not included) Designed, assembled, and calibrated in USA

Condition:	New: A brand-new, unused, unopened, undamaged item in its original packaging (where packaging is applicable). Packaging should be the same as what is found in a retail store, unless the item is handmade or was packaged by the manufacturer in non-retail packaging, such as an unprinted box or plastic bag. See the seller's listing for full details. ...	MPN	DMMCheck Plus
Country/Region of Manufacture	United States