Based on your location and organization it appears you are a test lab.....which means that uncertainty works different than it does for calibration.....
That is not a bad thing, it is simply the reality of uncertainty.
One point to consider.....in some fields of testing, uncertainty is valid and will give useful information.....in a field such as agriculture the numbers may have any value, which means they tell you nothing.....but you still need them for accreditation.
First, the procedure should be general in the approach and refer to other sources for specific calculations. Next, you should develop a method of identifying the sources of uncertainty and quantifying them. The quantification will change depending on what you are dealing with.
As an example, if you are testing wood the test results from a moisture content and density test will vary by species and method used. The actual test results - whatever they may be - are your Type A, or random, contributions. Typically for a test lab this is the primary driver of the uncertainty numbers.
List all the Type B, or systemic, contributions.....you will find that calibration of your instrumentation has almost no input whatsoever in a test method, but must be accounted for. Quantify the uncertainties that you can.....document the contributions that cannot be quantified so you have addressed them.....some contributions may be easier with an arbitrary assigned value, just make sure it is realistic.....
Then perform the calculations as a calibration lab would.....for your Type A, if there is only one reading, unfortunately it is the number so a standard deviation may not be possible.
Hope this helps.
Hershal