bigcanuknaz
New Member
Hi all:
This is my first time at this forum. I spent a bit of time reading, and understood some of it, but most is over my head. I think this will be a fantastic place for me to get advice, on designing my greenhouse automation projects.
My problem:
We just rented a new greenhouse that has gutter opening roof vents, instead of peak opening vents. When it rains, you typically set the vents to open only a few inches, and less on the windside than on the leeside. This works fine with peak vents. But for gutter vents (vents that pivot on the peak of the greenhouse and open from the gutter with another greenhouse connected to the other side of the gutter), if it rains very heavy, then the gutter can overflow into the greenhouse making a mess. In this case, you want to close the roof (gutter) vent, open side vents, and turn on exhaust fans.
I am looking for a rain sensor, that measures how hard it is raining, with a reasonably fast response time on the order of 20 sec to a minute.
My search:
I looked and inquired from our equipment suppliers to no avail. Typical "tipping bucket sensors" measure on the order of 1/8 of an inch of rain, and are used primarily for measuring the amount of rain that falls over the period of about a day. They are accurate, but have a slow response time. The main one i looked at also had a very short pulse, that would require a frequency rather than just a dry contact input into our controller.
I found this homemade sensor in my search:
Electronic Rain Sensor
It looks easy to build, and will be quite easy to adjust (either the funnel size, and/or the size of the dual bucket). The only question I have is what kind of sensor should I use?
My control system (Argus Control Systems Inc - Titan controller) will take as inputs:
1. 0-5 vdc
2. 4-20ma (same input using a resistor)
3. resistance measurement (dry contact) (same input)
4. frequency input (different input)
My first thought is to just hook up resistance measurement from the aluminum tipping bucket to a contact point on one side of the bottom of the PVC tee (where the inductive sensor is in the homemade sensor referenced above). I could easily adjust the resistance level, to get an on/off input depending on whether the bucket is in contact or not with the contact point.
The control program would be easy for me to set up.
My question:
Is using just a "dry contact" (ha ha ha, in the rain)the best way to go? Have you any other comments?
Thanks so much. I look forward to posting other questions in the future.
naz
This is my first time at this forum. I spent a bit of time reading, and understood some of it, but most is over my head. I think this will be a fantastic place for me to get advice, on designing my greenhouse automation projects.
My problem:
We just rented a new greenhouse that has gutter opening roof vents, instead of peak opening vents. When it rains, you typically set the vents to open only a few inches, and less on the windside than on the leeside. This works fine with peak vents. But for gutter vents (vents that pivot on the peak of the greenhouse and open from the gutter with another greenhouse connected to the other side of the gutter), if it rains very heavy, then the gutter can overflow into the greenhouse making a mess. In this case, you want to close the roof (gutter) vent, open side vents, and turn on exhaust fans.
I am looking for a rain sensor, that measures how hard it is raining, with a reasonably fast response time on the order of 20 sec to a minute.
My search:
I looked and inquired from our equipment suppliers to no avail. Typical "tipping bucket sensors" measure on the order of 1/8 of an inch of rain, and are used primarily for measuring the amount of rain that falls over the period of about a day. They are accurate, but have a slow response time. The main one i looked at also had a very short pulse, that would require a frequency rather than just a dry contact input into our controller.
I found this homemade sensor in my search:
Electronic Rain Sensor
It looks easy to build, and will be quite easy to adjust (either the funnel size, and/or the size of the dual bucket). The only question I have is what kind of sensor should I use?
My control system (Argus Control Systems Inc - Titan controller) will take as inputs:
1. 0-5 vdc
2. 4-20ma (same input using a resistor)
3. resistance measurement (dry contact) (same input)
4. frequency input (different input)
My first thought is to just hook up resistance measurement from the aluminum tipping bucket to a contact point on one side of the bottom of the PVC tee (where the inductive sensor is in the homemade sensor referenced above). I could easily adjust the resistance level, to get an on/off input depending on whether the bucket is in contact or not with the contact point.
The control program would be easy for me to set up.
My question:
Is using just a "dry contact" (ha ha ha, in the rain)the best way to go? Have you any other comments?
Thanks so much. I look forward to posting other questions in the future.
naz