using System;
using System.Text.RegularExpressions;
 
public class Test
{
public static void Main()
{
 
Regex.Match(
    @"Time\tChannel 1 (mV)\tChannel 2 (mV)\tChannel 3 (mV)\tChannel 4 (mV)\tChannel 5 (mV)\tChannel 6 (mV)\tChannel 7 (mV)\tChannel 8 (mV)\tChannel 1_cal (mg/L)\tChannel 2_cal ()\tChannel 3_cal ()\tChannel 4_cal ()\tChannel 5_cal ()\tChannel 6_cal ()\tChannel 7_cal ()\tChannel 8_cal ()\tMotor 1 (mm)\tMotor 2 (mm)", 
    @"\\tChannel [0-9]* \(mV\)"
).Groups[0].Captures.Count;
 
}
}

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