In Calibration.java if one looks at function setUnit ( or setXUnit ) the unit gets sanintized! => if you call it with "um" it changes into "µm"

BUT: for setYUnit and setZUnit this is not done!
SUGGESTED BUGFIX:

private static String sanitizeUnit( String unit ) 
{
    if (unit==null || unit.equals("")) {
	return "pixel";
    } else {
	if (unit.equals("um")) return "\u00B5m";
		return unit;
    }
}
	
/** Sets the default length unit (e.g. "mm", "inch"). */
public void setUnit(String unit) {
 	this.unit = sanitizeUnit( unit );
 	units = null;
}
 	
/** Sets the X length unit. */
public void setXUnit(String unit) {
	setUnit(unit);
}

/** Sets the Y length unit. */
public void setYUnit(String unit) {
        yunit = sanitizeUnit( unit );
}

/** Sets the Z length unit. */
public void setZUnit(String unit) {
 	zunit = sanitizeUnit( unit );
}