Question: How to send negative measured numeric in OBX segment of ORU\_R01 profile for PCD DEC profile using HL7 2.6 ??

and also where i can find that requirement defined by IHE.. 

-Thanks-

Answer: 
Since you have to define a data type for each Observation Value (OBX.5), your question is actually how to use HL7 data types to code negative values. For example, the HL7v2 standard defined NM as: 

> 
> A number represented as a series of ASCII numeric characters consisting of an optional leading sign (+ or -), the digits and an optional decimal point.
> 
> 
> 

Check HL7v2.6 Chapter 2A for other data types.
Here is a link to the IHE Pathology and Laboratory Medicine [Technical Framework](http://www.ihe.net/Technical_Frameworks/#PaLM) which contains their requirements.