Unexpected results from conversion of unit expression

[incansvl]

Note- these results were taken from the interactive demo available at https://ucum.nlm.nih.gov/ucum-lhc/demo.html.

Note: Test value deliberately chosen to be challenging/confusing for UCUM but the syntax is correct I believe.

Item	Operation	Input	Output (Result)	Comment
1	Convert to L-1.s-1	(78.2).(mmol/L)/s	9.394533251999998e+22 L-1.s-1	The string "78.2" here is interpreted by UCUM as 78 x 2, so this expression should evaluate to 156.mmol/L/s . How the numerical value ends up beginning with a 9 and with an exponent of 10^22 is hard to understand

[Paul Lynch]

I think the output is correct in this case. The destination units do not contain "mmol", so your result gets multiplied by a conversion factor of 6.022e+23 * 1e-3.

[incansvl]

Very good point, i'd forgotten the impact of UCUM not including Moles as a base unit in this case (although I gather the two different NIH implementations actually differ in this respect?).

Thanks for the quick reply.

[Paul Lynch]

Yes, the API version would probably not permit the conversion because it has mol as a base unit.