Hello,
I bought a BM869s uncalibrated and tried to test its accuracy.
I have a LB02A which I also hadn't tested before against a calibrated source and finally got access to a keithley 2000 and a HP 34401, both calibrated back in may 2019.
I measured LB02A against Brymen and Keyhtly and HP.
Here the chart of deviation against set values on the LB02A of the 3 equipments for Volt and mV settings of LB02A.
What can I conclude? Bryman is accurate within 1 mV in volt range and within 50 uV in mV range, and LB02A has an accurate set value between 2,5 and 3 v and voltage progression given b "V = Set V + 0,0004 x SetV - 0,0013"?
Unfortunately I checked with Brightwin and they informed me the LB02A cannot be calibrated by end user, but even if I would try to calibrate via the internal potentiometer which I will not do without understanding what it does, this seems not a linear error. Maybe some error due to DAC?
BR,
Jorge