A process for the manufacture of technical grade (meth)acrylic acid, the process comprising producing a hydrated, gaseous reaction product obtained from the gas-phase oxidation of at least one (meth)acrylic acid precursor followed by first dehydrating the reaction product and then concentrating the reaction product in a finishing zone, the reaction product comprising water, acetic acid and (meth)acrylic acid, the process comprising the steps of: A. Cooling the gaseous reaction product; B. Using a coupled, two-tower distillation system comprising two distillation towers connected such that a tails stream from the base of a first tower is fed directly or indirectly into a top of a second tower while an overhead stream of the second tower is fed directly or indirectly into a base of the first tower, dehydrating the cooled gaseous reaction product in a first distillation tower to produce a gaseous overhead stream and a liquid tails stream, wherein the dehydrating step is carried out without using solvent that forms an azeotrope with water; C. At least partially condensing the gaseous overhead stream in a condenser having an operating temperature to form a condensate, and returning at least a portion of the condensate to the first distillation tower; D. Creating an electronic signal from an on-line, near infrared spectrometer, the signal based on at least one of the water, acetic acid and (meth)acrylic acid content of at least one of (i) a tails stream from the base of the first distillation tower, and (iii) an overhead stream from a second distillation tower that is coupled to and receives the tails stream from the first distillation tower; E. Sending the electronic signal created in to a means for controlling the operating temperature of the condenser that is coupled to and receives the overhead stream from the first distillation tower, wherein the means for controlling the operating temperature of the condenser comprises a microprocessor in which the signal is compared against a pre-determined setpoint or standard, and F. Increasing, decreasing or maintaining the operating temperature of the condenser based on the signal created in, thereby producing a side draw product stream of technical grade acrylic acid from the second column containing at least 98.5 wt % acrylic acid, less than 0.5 wt % water and less than 0.4 wt % acetic acid. A. Cooling the gaseous reaction product; B. Using a coupled, two-tower distillation system comprising two distillation towers connected such that a tails stream from the base of a first tower is fed directly or indirectly into a top of a second tower while an overhead stream of the second tower is fed directly or indirectly into a base of the first tower, dehydrating the cooled gaseous reaction product in a first distillation tower to produce a gaseous overhead stream and a liquid tails stream, wherein the dehydrating step is carried out without using solvent that forms an azeotrope with water; C. At least partially condensing the gaseous overhead stream in a condenser having an operating temperature to form a condensate, and returning at least a portion of the condensate to the first distillation tower; D. Creating an electronic signal from an on-line, near infrared spectrometer, the signal based on at least one of the water, acetic acid and (meth)acrylic acid content of at least one of (i) a tails stream from the base of the first distillation tower, and (iii) an overhead stream from a second distillation tower that is coupled to and receives the tails stream from the first distillation tower; E. Sending the electronic signal created in to a means for controlling the operating temperature of the condenser that is coupled to and receives the overhead stream from the first distillation tower, wherein the means for controlling the operating temperature of the condenser comprises a microprocessor in which the signal is compared against a pre-determined setpoint or standard, and F. Increasing, decreasing or maintaining the operating temperature of the condenser based on the signal created in, thereby producing a side draw product stream of technical grade acrylic acid from the second column containing at least 98.5 wt % acrylic acid, less than 0.5 wt % water and less than 0.4 wt % acetic acid.