CHAPTER 4 TESTING4.2.2 Adjusting Off Center Load1. Place a weight, close to full capacity, at the pan center. Press TARE.2. Move the weight to the back edge and note the display.3. Move the weight to the front edge and note the display.4. Move the weight to the right edge and note the display.5. Move the weight to the left edge and note the display.Figure 4-4 shows the front part of the scale with the Allen Keys sticking out in the back.The arrows show the key rotation directions required to bring the weight within tolerancespecification. (See Table 1-2 – Discovery Balance Model Specifications.)Figure 4-4. Allen key rotation directions needed forback-edge-heavy, back-edge-light, right-edge-heavy and right-edge-light conditions.The “+” sign depicts the part of the Pan that is “heavy.” It is a positive value, that is,greater than the tolerance specification. The opposite side of the Pan, which is “lighter,”has a negative value, that is, less then the tolerance specification.When moving the weights, observe the Display value readings to see if they havepositive or negative values.In Figure 4-4, the top-left graphic shows the key rotation direction needed if the backedge of the scale Pan has a “heavy” positive value (greater then the tolerancespecification). The top-right graphic shows the key rotation direction needed if the backedge has a “lighter,” negative value, (less than the tolerance specification). Thegraphics in bottom-left and bottom-right, show key rotation directions for right-edge-heavy and right-edge-light conditions.The purpose of these adjustments is to ensure that weight reading discrepancies on thePan are diminished to close to zero and within tolerance specification.Discovery Balance Service Manual 4-3 Ohaus Corporation www.ohaus.com
