Add commonly used custom units

[dmullen17]

Add commonly used custom units - much like the example solr queries section.

Some of the top of my head:
[] partsPerMillion
[] partsPerThousand
[] wattsPerSquareMeter

[dmullen17]

Adding some of that I have stored in a script here:

custom_units <- data.frame(
  id = c('partsPerThousand', 'micromolesPerGram'),
  unitType = c('dimensionless', 'amountOfSubstanceWeight'),
  parentSI = c(NA, 'molesPerKilogram'),
  multiplierToSI = c(NA, 10^9),
  abbreviation = c('ppt', 'umol/g'),
  description = c('parts per thousand', 'micro moles per gram'),
  stringsAsFactors = FALSE)

unit_list <- set_unitList(custom_units, as_metadata = T)
doc$additionalMetadata <- eml$additionalMetadata(describes = NULL,
                                                 metadata = unit_list)

[jeanetteclark]

Good idea. I'll add others as I think of them but PSU, decibar, micromolePerMeterCubed are some I'm dealing with now that I see often