my variable 'dailypeakpower_t' isn't changing live the data-unit from the gauge, but does change the '#test'.
i can't figure out why?

test.php
Code:
<?php
include('C:/Sunprofit/DATA/Solarlog/sunprofit.php');
if (isset($_GET['pac_t'])){
echo $pac_t;
exit;
}
if (isset($_GET['dailypeakpower_t'])){
echo $dailypeakpower_t;
exit;
}
?>
<!DOCTYPE html>
<html lang="nl">
<head>
<title>Test</title>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js"></script>
<script type="text/javascript" src="gauge.min.js"></script>
<script type="text/javascript" >
function isset ( strVariableName ) { 
    try { 
        eval( strVariableName );
    } catch( err ) { 
        if ( err instanceof ReferenceError ) 
           return false;
    }
    return true;
 }
if((isset(dailypeakpower_t))){
	var dailypeakpower_t = parseInt('33');
}
function setDU(){
	el = document.querySelector('#gauge1');
	el.dataset.units = dailypeakpower_t; 
}
</script>
</head>
<body>
<div id="meter">
    <canvas class="meterGroot" id="gauge1" width="400" height="400"
            data-type="canv-gauge"
            data-title="Totaal"
            data-min-value="0"
            data-max-value="1000"
            data-major-ticks="0 1000"
            data-minor-ticks="2"
            data-stroke-ticks="true"
            data-units="1"
            data-value-format="3.2"
            data-glow="true"
            data-animation-delay="10"
            data-animation-duration="200"
            data-animation-fn="bounce"
            data-colors-needle="#000 #000"
            data-highlights=""
            data-onready="setInterval( function() { Gauge.Collection.get('gauge1').setValue(pac_t)}, 1000); "
    ></canvas>
<div id="test"></div>
<script type="text/javascript" >
	setInterval(function(){
		setDU();
		document.getElementById('test').innerHTML=dailypeakpower_t;
		console.log(dailypeakpower_t+' dailypeakpower_t');
	}, 1 * 1000);
</script>
<script type="text/javascript" >
$(function(){
    setInterval(function(){	
		$.get('<?php echo $_SERVER['REQUEST_URI']; ?>?pac_t',function(num){pac_t = num;});
		$.get('<?php echo $_SERVER['REQUEST_URI']; ?>?dailypeakpower_t',function(num){dailypeakpower_t = num;});
    }, 1 * 1000);
}); 
</script>
</body>
</html>