Some height gagea do not have an adjustable vernier scale. A misalignment in the vernier abd the beam zero marks may indicate a loose vernier slide, an incorrect scriber dimension, or a beam that is out of perpendicular with the base. Loose vernier slides may be adjusted and scriber dimrnsions can be corrected. However, if the beam is out of perpendicular with the basr, the instrument is unrealiable because of cosine error. A determination of such a condition can be made by an appropriate calibration process. All height gages, particularly those with nonadjustable verniers, must be treated with the same respect as any prrcision instrument that you will use.