How to reduce the sensing range of a PIR?

I am looking for some one to help me with a pir solution. Is there a way to reduce the sensing range of the 575L? I need it to sense a max of 3mts from the sensor.

 

You can get partway there by increasing the Time Threshold parameter on the Global tab from the default of 208ms to something larger. Try making it ~500ms and test it to see if that is sufficient.

A better way would be to swap out the 5753L for a 5753PEIRL. With this unit by default the unit sensitivity is assigned to Pot B. You can tweak the sensitivity by removing the decorative ring and adjusting Pot B with a screwdriver until you get the range you want.

 

Thanks Newman for the quick reply but the sensor I have is the 5751L. Will that still apply to this sensor? I could replace it with a 5753Peirl but it would have to be located on a corner, would that be a problem with these type of sensors because I see they advise against corner mounting.

 

I did a very low-tech solution to limit the scan 'width' of mine, I stuck a piece of insulation tape on the lens to limit the visible portion to a cetain area

Ingo

 

You don't have the same options with a 5751L. I'd suggest you start with editing the Time Threshold parameter and see how that goes first.

 

Increase Sensitive of 5753L

Dear Mr.NewMan,

Is it mean I can increase the sensitivity by setting long press time to minimum value 96ms. Because in my installation, the sensor also mount arround 2.4m but it is not sensitive enough, I must go as close as 2m to trigger the sensor!!!

May you give me advise to make them more sensitive? Currently I leave all at default setting, because you told me before sensor is set as highest sensitive from factory.

Is it affected by system clock or cable wiring?

Thank you in advance!
Best Regards

 

If you have a 5750WPL or 5751WPL you will get maximum sensitivity with a Time Threshold value of 96ms. Normally they ship with this value as the default, so if your unit is any different you can change it back to 96ms. The 5753 series sensors have a minimum Time Threshold value of 208ms.

The sensitivity of the units is not affected by these.