[volt-nuts] Fluke 895A

[Joseph Gray]

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