Hello Frank, here is my result from tilting the LTZ1000A in battery supply mode. So connection is only at the output to a LT1043-based 2:1 voltage divider and my 24-bit battery supplied LTC2400 based temperature compensated ADC. Connection to the PC is via photocouplers. So the whole cirquit is floating. To reduce drift of the ADC I had to heat the ADC to about 28 degrees with a temperature controlling cirquit. Since a single ADC-measurement has about 10-20uVpp noise I averaged the measurements within 1 minute (around 330 single measurements) to get the noise to around 1uV referred to the ADC input. (giving 2uVpp referring to the LTZ). For evaluation of the tilting effect I changed orientation every 10 minutes giving 5 minutes to settle the new value and averaged the last 5 minutes. Resulting in about 1uVpp noise referred to the LTZ. with the offset voltage of -0.01706 mV from the voltage divider the final results are: Time orientation verbal. coded LTZ voltage diff to zero diff (ppm) 15:20 0 degrees pins down 0 (7143.76684 mV) ( 1.60 uV) ( 0.22 ppm) (invalid) 15:30 90 degrees pin8 is up 1 7143.76468 mV -0.56 uV -0.08 ppm 15:40 180 degrees up side down 2 7143.76548 mV 0.24 uV 0.03 ppm 15:50 270 degrees pin4 is up 3 7143.76656 mV 1.32 uV 0.18 ppm 16:00 D-SUB up pin6 is up 4 7143.76504 mV -0.20 uV -0.03 ppm 16:10 D-SUB down pin2 is up 5 7143.76552 mV 0.28 uV 0.04 ppm 16:20 0 degrees pins down 0 7143.76524 mV 0.00 uV 0.00 ppm (zero) 16:30 D-SUB down pin2 is up 5 7143.76548 mV 0.24 uV 0.03 ppm 16:40 D-SUB up pin6 is up 4 7143.76400 mV -1.24 uV -0.17 ppm 16:50 270 degrees pin4 is up 3 7143.76580 mV 0.56 uV 0.08 ppm 17:00 180 degrees up side down 2 7143.76508 mV -0.16 uV -0.02 ppm 17:10 90 degrees pin8 is up 1 7143.76440 mV -0.84 uV -0.12 ppm 17:20 0 degrees pins down 0 7143.76516 mV -0.08 uV -0.01 ppm The result at 15:20 is off against 16:20 and 17:20 so I decided to exclude it from the evaluation. Since all values are near or well within my noise figure I cannot really tell wether the values are real or simple accidently. But all changes are below 2uV or 0.3ppm. >From the many measurements I tried up to now I can tell that orientation 3 (270 degrees with Pin 4 of the LTZ device in most upper position) has had always a positive deviation against 0 degrees with pins pointing downwards. Note that my orientations are not the same as yours. My 180 degree orientation with Pins up side down will correspond to your 0 degrees orientation so I have referenced to the LTZ-pins in verbal description. Attached you will find the the measurement with raw values of the ADC (after 2:1 divider) giving around the halved values. enjoy Andreas Jahn