HI9829-10/11 is for premium quality 10 ppm and 100 ppm (mg/L) Ammonium (as N) calibration standards. These standards are used to calibrate the HI7609829-10 ammonium ISE. Each sachet has the lot number and expiration date stamped on it. The sachet is made of light block and air-tight foil ensuring freshness each time one is used. The HI9829-10/11 contains 10 sachets, each of the 10 ppm and 100 ppm Ammonium Calibration Standard (as N). Each sachet contains approximately 20 mL of buffer.