@echo off

setlocal enabledelayedexpansion
set row=0

set inFile=merged.csv
set outFile=final.csv

if exist "%outFile%" del "%outFile%"

>%outFile% (
  for /f "tokens=1,* delims=," %%A in (%inFile%) do (
    set /A row+=1
	set time=%%A
	set data=%%B

REM : edit column headers and values here

	set head=machine,label
	set body=0,inlet-sparger

	if !row! lss 2 (
	REM	: I have no idea why this needs to be separated
REM : ...but it has to, or it doesn't work

	  echo | set /p=!time!
	  echo | set /p=,!head!,
      echo !data!
    ) else (
	  echo !time!,!body!,!data!
	)
  )
)

if exist "%inFile%" del "%inFile%"