How to set interval in DeviceMotionEvent javascript

Question

I have code which is written:

if ('DeviceMotionEvent' in window) {   

    deviceMotion = new DeviceMotionEvent("devicemotion", {interval: 20, acceleration:DeviceMotionEventAcceleration});
        
    window.addEventListener("devicemotion", onDeviceMotion, false); 

    window.dispatchEvent(deviceMotion);
} 

function onDeviceMotion(eventData){
    
    accelerationHandler(eventData.acceleration);

    intervalHandler(eventData.interval);
    
}

function accelerationHandler(acceleration) {
    
    document.getElementById("ac_x").innerHTML = acceleration.x.toFixed(precision);

    document.getElementById("ac_y").innerHTML = acceleration.y.toFixed(precision);

    document.getElementById("ac_z").innerHTML = acceleration.z.toFixed(precision);
}

function intervalHandler(interval) {
    document.getElementById("ac_interval").innerHTML = interval;
}

I want to set the interval as 20 but the above code gives me a default interval 16.
How can i properly set the interval?