Deflection Method: Inspection

Apply a force of 98 N (10 kgf, 22 lbf) and measure the deflection between the power steering pump pulley (A) and the crankshaft pulley (B).
Deflection:

Used Belt: 13.0-16.5 mm (0.51-0.65 in.)

New Belt: 8.5-11.0 mm (0.33-0.45 in.)

Fig 1: Measuring Belt Deflection
Courtesy of AMERICAN HONDA MOTOR CO., INC.
If you installed a new belt, run the engine for 5 minutes, then readjust the belt to the used belt specifications.
Adjustment
Loosen the power steering pump mounting nut (A) and bolt (B).

Fig 2: Loosening The Power Steering Pump Mounting Nut And Bolt
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the adjusting nut (C) to get the proper belt tension, then retighten the mounting nut and bolt.
Start the engine and turn the steering wheel from lock-to-lock several times, then stop the engine and recheck the tension of the belt.