OHAUS NV212 Service Manual

Also see for Navigator NV1101: Instruction manual Instruction manual

Contents

OHAUS NV212 Service Manual Manual pdf 30 page image

CHAPTER 3 MAINTENANCE PROCEDURESOhaus Corporation www.ohaus.com 24 Navigator Series Service ManualNV Models NVL and NVT ModelsFigure3-6. Down Stop Adjustment ScrewsTo adjust the down-stops on the applicable models follow the procedures below. Models withoutadjustable down-stops need no action.To ensure full weight reading:The proper down-stop adjustment will allow full weight reading provided the center of the mass isless than ½ the distance from the pan center to the pan edge. To allow for tolerance this adjustmentis being done at 120% of scale capacity or at scale capacity but ¾ of the distance to the pan edge.To protect the load cell:To protect the load cell from physical damage the down-stops should touch at about 200% of scalecapacity. Again to allow for adjusting tolerance the adjustment is made using a 150% weight.The adjustment screws in the Sub-Pan can be adjusted with a #2 cross-recess (Phillips) screwdriver. Each adjustment screw should contact the Base when 120% to 150% of the scale capacity isplaced in the center of the 4 quadrants of the scale. The Top Housing must be removed to visuallycheck if the down-stops are touching. Turn the adjustment screw counterclockwise to increase theclearance and clockwise to decrease the clearance.An easy method to check the down-stop adjustment is to use the scales weight reading to detect ifthe down-stop is touching. This method can only check if the down-stop is set too close preventingaccurate weighing.1. Place 100% scale’s capacity in the center of the Pan.2. Note the reading.3. Move the mass ¾ of the way (between the center and the edge) to the front of the Pan.Note any significant difference in the displayed weight reading.4. Repeat the test for the back, left, and right position of the Pan.5. If there was a weight reading change turn the adjustment screw nearest the quadrantcounterclockwise ¼ turn. Repeat the test to see if it is corrected.6. If the weight is placed at the edges of the pan there may be a weight change which indicatesthe down-stop is working and this is okay.