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Did you get a calibration certificate from VPG?
I have decided to purchase a 4-wire lead 10 kΩ resistor Y473310K0000S0L (VHA518-11Z) with post-manufacturing operations (PMO) from Vishay Precision Group to act as a transfer standard for my Advantest R6581T 8.5-digit multimeter. My plan is to mount the resistor in a shielded box and crimp LowThermal ring terminals onto the leads so that I can fasten them to 2758 Series LowThermal binding posts. This should avoid any potential soldering damage and allow simple disassembly if required in the future. If anyone is interested, I have attached Technical Note 103 on soldering foil resistors. The applications engineer provided me with some additional options (there are likely more, but some might be exclusive to manufacturers and other more valuable customers):
- perform a
resistance check and record with each resistor and send the data to me OR Vishay can supply a
NIST certification - Vishay can also supply a non-standard lead at 80 mm [3.15 in] length instead of 25.4 mm with optional sheathing (I am merely informing members and do not intend to go with these options)
My assumption is that the VHA518 resistor will experience the most amount of change during the first year. This is why PMO is desirable for my resistance standard application. According to the Field Design Engineer, the procedure for PMO is custom and based on the clients' design intention. They did not elaborate on their techniques, but they said that they would focus on stability in order to ensure performance via a
minor PMO for this single resistor purchase. Would it be practical to choose the NIST certificate option that likely costs significantly more, or should I go with the simple 'resistance check with record' option and have the resistor checked again in a year's time by a calibration lab? In practice, the minor PMO should remove much of the initial drifting, but I do not have enough information to quantify the effectiveness of this optional step. My guess is that I am overthinking things and I should simply be grateful for their 'check with record' offer. What do you think?
Regards.