PicoStrain: Strain Gauge / Load Cells
Precision of a Single Measurement
circuit, the discharge time is about t = 0.7*RSG*CLoad
In measurement range 2 the time interval measurement uses not only the high-speed unit of the TDC but also the reference clock (pre-divider). Doing this the measurement range of the TDC is extended to 100 µs. This allows update rates up to 10 kHz. For higher update rates the discharge time must be reduced. At update rates higher than 10 kHz measurement range 1 is recommended.
The following values are recommended for measurement range 2:
As long as the update rate is not higher than 5 kHz we recommend working with measurement range 2. Setting the discharge time to 50 -100 µs, PS021 has the performance shown in the table on the right
General Circuit Features
PS021 internally improves the precision of the measurement results by averaging. The measuring principle guarantees that no significant systematic errors affect the result. The standard deviation is improved by the square root of the averaging rate.
(2 kHz update rate):
|5 V||0.66 µV||1.15 µV|
|3 V||0.51 µV||0.88 µV|
|2.5 V||0.57 µV||0.98 µV|
|5 V||0.026 µV||0.045 µV|
|3 V||0.024 µV||0.041 µV|
|2.5 V||0.024 µV||0.041 µV|