Chemical delivery systems and methods of delivery

A method of mixing a first liquid chemical with a second liquid chemical and delivering the mixture in a system comprising a multi-reservoir load cell assembly, including a main reservoir, a buffer reservoir, and a load cell, comprising:

• isolating the buffer reservoir from the main reservoir;
• supplying a first liquid chemical to the main reservoir until the multi-reservoir load cell assembly determines the main reservoir has a sufficient amount of the first liquid chemical;
• supplying a second liquid chemical to the main reservoir until the multi-reservoir load cell assembly determines the main reservoir has a sufficient amount of the second liquid chemical;
• mixing the first liquid chemical with the second liquid chemical;
• and
• supplying mixture of the first liquid chemical and the second liquid chemical from the main reservoir to the buffer reservoir.

A method of precise non-pulsed liquid chemical delivery in a system comprising a multi-reservoir load cell assembly, including a main reservoir, a buffer reservoir, a load cell, comprising:

• supplying pressurized gas to the main reservoir;
• isolating the buffer reservoir from the main reservoir;
• once the buffer reservoir is sealed, evacuating the main reservoir causing liquid chemical flow into the main reservoir until the load cell and the logic device determine the main reservoir is refilled with liquid chemical;
• supplying the liquid chemical from the buffer reservoir without negative pressure or a difference in pressure;
• once the main reservoir has refilled, stopping vacuum generation to the main reservoir and supplying low pressure gas to the main reservoir and to the buffer reservoir;
• allowing the liquid chemical from the main reservoir to flow into the buffer reservoir;
• and
• supplying high pressure gas to the main reservoir during and/or after liquid chemical flow from the main reservoir to the buffer reservoir.