Anyone on here pretty familiar with these? I was wondering how the spec works for the 100 PSI precision range? There are 2 specs and I am kind of arguing with our other tech as to how to properly use the PPC4.
It tells you in the footnotes of the specification how the total accuracy is derived.
±0.008 % of reading from 30 % to 100 % of Q-RPT span. Below 30 %; ±0.0024 % of Q-RPT span.
Ok so to me that means that it is a 100 PSI range so 0-30 PSI is ±0.0024 % of Q-RPT span. The person I work with is arguing with me that it is 30% of 30 PSI since that premium sensor is set up to up to work to the full scale that is put in. IE if you put in 30 PSI as full scale it is 9 PSI so it is only ±0.0024 % of span up to 9 PSI then above that it is ±0.008 % of reading. I feel like this is wrong but after she beat my ear on this issue for like an hour now it kind of makes sense to me.
She's wrong.
That accuracy spec is for 30-100% of the range of the transducer. Below 30% to zero is the other spec.
30 psi on the 100 psi transducer would be ±0.008% of 100, 29 psi would be ±0.0024% of 100.
Amazing how men start to believe what the woman says after about an hour of them constantly arguing.
Exactly as MIRCS says, per the foot notes is 30% of the Q-RPT range...
By her logic I could set a range of 3 psi and claim .0024% of 1 psi....
At pressures below 30 PSI, it basically reaches a "noise floor" and flat-lines at 0.0024% of full scale. Mensor also has a confusing "double spec" for their CPC line of pressure controllers called "Intelliscale-50"; or 0.01% IS-50. That means if the full range is 100 PSI, it's 0.01% of half the range (i.e. 0.01% of 50 PSI) from 0 to 50 PSI, and above that, it's 0.01% of reading. Looking at it on a graph, it flat-lines from 0 to 50% of range, then goes up from there.
Of course; all this is marketing B.S. that goes on between the different makers of pressure controllers in order to sell their product.
She is most likely correct.
But it depends on which class of reference transducer is installed.
If it is a Standard Class 100PSI, then its precision is good to 0.008%RDG down to 30PSI where it becomes fixed (30% of full scale).
A Premium Class 100PSI can utilize the AutoRange feature so you could get 0.005% RDG precision down to 9PSI, where it would then become constant.
The Premium spec, which is admittedly a bit tedious to figure out, is 0.005%RDG precision in the upper 70% of the active AutoRange. And a given AutoRange can have an "effective Full Scale" that is as low as 30% of the transducers max capacity.
So, 30% of 30% will get you a 0.005%RDG precision down to 9%, which is 9PSI on a 100PSI transducer.
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