Cell-Phones, Cordless-Phones, and any radio-frequency device can cause temporary interference and 
cause the scale to temporarily not work properly. Please do not use any electronic device near the scale. 
Just like in an Airplane, do not use your cell-phone near the scale when it is in use. While there is NO risk 
of permanent damage to the scale, interference can cause an incorrect calibration or incorrect weight 
readings.  

CALIBRATION

When to calibrate - calibration is almost never required.  

If the scale is inaccurate, calibration may be desired when the scale is first set up for use, or if the scale is 
moved to a different altitude or gravitation. This is necessary because the weight of a mass in one 
location is not necessarily the same in another location. Also, with time and use, mechanical deviations 
can occur.  

How to calibrate  

**The UL-30/35 requires a 10kg calibration weight to calibrate. The UL-50/55 and UL-75 require a 20kg 
calibration weight. (you can use a combination of weights such as 5 2kg weights)**