Using C++ to control an instrument, need a consistent wait function

Question

I am controlling an instrument using C++.

I am trying to create instrument dwell periods that are consistent so the resulting data reads are more consistent. I am attempting to define a sleep function that uses a while loop to hold up the program for a certain amount of time.

My issue is the dwell times are inconsistent.

#include <stdio.h>
#include <tchar.h>
#include <chrono>
#include <thread>
#include <ctime>
using namespace std;
#include <windows.h>

void Dwell(float seconds){
    clock_t startClock = clock();
    float secondsAhead = seconds * CLOCKS_PER_SEC;
    // do nothing until the elapsed time has passed.
    while(clock() < startClock+secondsAhead);
    return;
}

//I then use chrono to time the dwell

int main()
{
    using std::chrono::high_resolution_clock;
    using std::chrono::duration_cast;
    using std::chrono::duration;
    using std::chrono::milliseconds;
    auto t1 =high_resolution_clock::now();
    Dwell(1);
    auto t2 =high_resolution_clock::now();
    auto ms_int = duration_cast<milliseconds>(t2-t1);
    duration<double, std::milli> ms_double = t2-t1;`
    

I keep getting less than the time I put into my function Dwell. I call Dwell expecting a wait time of 1 second, but I get varying results, all less than 1 second, e.g. 800 ms, 759 ms, 912 ms, etc. I am hoping to get accurate and consistent dwell times within 100 us of the requested dwell time.