how many ppm are in 1 ppt?
To convert ppm readings to ppt, divide the ppm reading by 1000. For example a reading of 5000 ppm = 5000 ppm/1000 = 5.00 ppt. To convert ppt readings to ppm, multiply theppt reading by 1000. For example a reading of 4.00 ppt = 4.00 ppt x 1000 = 4000 ppm.