Since last night, I have been playing around with a borrowed 895A. Since it hasn't been used in many years, I put it on the variac and brought it up slowly.
It was last calibrated in 1991 and still had the non-tamper labels on various screws. I opened it up not only to look at it, but to blow out some dirt (Real dirt, not just dust. I need to take this apart some and carefully clean the insides.). The plastic cover over the double-zeners is marked "12.734006" and dated 1968. Wow, down to the microvolt. Just messing around, I measured a used 9 V battery. On the 100 uV scale and with some interprolating of the last dial, I read 9.189795 V at null (with a tiny bit of wobble on the needle). On my 3.5 digit Extech handheld meter, I read 9.17 V. A Keithly 5.5 digit read 9.1897 (flipping between 7 and 8). And last, my 3478A read 9.1912 (flipping between 2 and 3). Nothing is calibrated (yet), but I would tend to think that the 895A is still pretty accurate after all these years. I have decided not to send the 3478A for calibration at this time. I am looking for a 3457A and will send it for calibration instead. Later, I may also send the VS330 in (I have too many expensive interests). BTW, If the consensus is that you would rather not see my ramblings as I experiment with this stuff, let me know and I'll shut up. Joe Gray W5JG _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
