I think I've solved it by editing the "conds.php" file like this:
$JSONdata["press"] = conds_convertBaro($Data[10],$uomBaro,$sBaroUOM); // WD Sample= '30.138 in.'
$JSONdata["pressTL"] = conds_convertBaro($Data[36],$uomBaro,$sBaroUOM); // WD Sample= '30.124 in.'
$JSONdata["pressTH"] = conds_convertBaro($Data[34],$uomBaro,$sBaroUOM); // WD Sample= '30.229 in.'
//$JSONdata["pressL"] = $WX['thb0seapress-amin']; // WD Sample= '26.001'
//$JSONdata["pressH"] = $WX['thb0seapress-amax']; // WD Sample= '30.569'
$JSONdata["pressL"] = conds_convertBaro($Data[36],$uomBaro,$sBaroUOM); // WD Sample= '26.001'
$JSONdata["pressH"] = conds_convertBaro($Data[34],$uomBaro,$sBaroUOM); // WD Sample= '30.569'