- Total hardness solution reference material (in terms of calcium carbonate),0.2μg/mL, matrix: H2O, 500ml
- Total hardness solution reference material (in terms of calcium carbonate),0.9μg/mL, matrix: H2O, 500ml
- Total hardness solution reference material (in terms of calcium carbonate),3.8μg/mL, matrix: H2O, 500ml
- Total hardness solution reference material (in terms of calcium carbonate),10μg/mL, matrix: H2O, 500ml
- Total hardness solution reference material (in terms of calcium carbonate),20mg/L, matrix: H2O, 20ml
- Total hardness solution reference material (in terms of calcium carbonate),100mg/L, matrix: H2O, 20ml
- Total hardness solution reference material (in terms of calcium carbonate),500mg/L, matrix: H2O, 20ml