C#写入数据不被覆盖

 private void timer3_Tick(object sender, EventArgs e)
        {
            try
            {

                using (FileStream fs = File.Open(@"C:\Users\FSY\Desktop\n.txt", FileMode.Open, FileAccess.ReadWrite))
                {
                    Byte[] infor = new UTF8Encoding(true).GetBytes(time + "\t空气温度" + Ram.sensor.a1 + "\r\n");
                    fs.Write(infor, 0, infor.Length);
                }
    }
    catch
    {
        FileStream fs = File.Open(@"C:\Users\FSY\Desktop\n.txt", FileMode.CreateNew);
        fs.Dispose();
    }
想做一个定时器实时写入数据到txt的程序，但是这样每次都会覆盖前一个数据，不知道该怎么改了，请各位大佬帮忙看看

FileMode.Open改为FileMode.Append试试

FileAccess.ReadWrite
改为
FileAccess.Append