Comparator pulse comparing issues

I'm working on a super smelter which includes 2 Comparator which are comparing the amount of blocks in a hopper vs how many blocks are in a hopper minecart. When the minecart has 1 stack and 51+ blocks and the hopper has two stacks, the hopper minecart gives off a signal as if the minecart had more blocks. But if you put more blocks into the hopper, the required amount of blocks in the minecart wont change until you have 2 stacks and 10 blocks in the hopper. Once you have 2 stacks and 10 blocks in the hopper, you need 2 stacks and 10 blocks to give out a redstone signal.