Ratiometric dating

I have a variety of bridge transducers (pressure, strain gage) with sensitivity of 1m V/V.Also, most 24-bit ADCs and analog frontend chips have a PGA with programmable gain between 1-128.

Zircons can be found in igneous rocks, metamorphic rocks and also in sedimentary deposits. A typical zircon crystal in granite for example is 100 - 300 micrometers across, although some can grow to several centimetres in size - especially in pegmatites (a very coarse-grained rock similar in composition to granite).

Another interesting property of Zircon is its durability.

"Everything which has come down to us from heathendom is wrapped in a thick fog; it belongs to a space of time we cannot measure.

We know that it is older than Christendom, but whether by a couple of years or a couple of centuries, or even by more than a millenium, we can do no more than guess." [Rasmus Nyerup, (Danish antiquarian), 1802 (in Trigger, 19)].

Zircons seem survive most geologic processes, including erosion, transport, and even high-grade metamorphism.

A very useful property of Zircons is their ability to accept high-field-strength elements.

Lava (properly called magma before it erupts) fills large underground chambers called magma chambers.

Most people are not aware of the many processes that take place in lava before it erupts and as it solidifies, processes that can have a tremendous influence on daughter to parent ratios.

As far as I can tell, I will still have all the benefits of the ratiometric connection, with only slight degradation in noise performance (due to the ADC performance with reduced Vref...

the closed-loop output resistance of the op-amp and its input voltage and current offsets appear to be negligible in this scenario) in terms of noise bits -- but the increased resolution more than compensates for the increase in noisy bits.

So Zirconium, which is one of the high-field-strength elements, can be substituted for another element, for example: Hafnium (Hf), Thorium (Th) or Uranium (U).

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