Split mustard seed

Rai dal

Measured by weight in g; no spoon conversion needed.

Instead of Split mustard seed

Mustard seed
Use the same weight and crush or grind; this is the same seed in whole form.
Yellow mustard seeds
Use the same weight, crushed; milder than black mustard, so increase slightly if you want heat.
Mustard powder
Use 60% of the weight; more concentrated, so mix into the dish gradually.