I have plaster walls in an old house the stud finder just keeps beeping how does this thing work?

Most stud finders have a sensitivity adjustment that should be carefully adjusted per instruction manual before use.
Failure to do this results in erroneous indications.

If you have adjusted exactly per the instructions with the same result the unit is probably faulty.

The stud finder works by picking up density of the product it is pressed and slid on..Turn your stud finder on make sure the ok light is on...then slightly press it against the wall or surface you are working with,,then slowly moved it right or left still against the surface. As the finder starts to detect more density "thickness" it will. Glow or beep depending what type you have..It will get brighter,louder or what ever it signals are while crossing the stud beneath the surface..keep moving until it stops then move back
again until it stops.....mark or note the position where the signal starts then find the middle...2x4's are 1 1/2 inches across...so center should be 3/4 of an inch...good luck..

The most important thing with fitting hardware is to find the studs in the wall for brick veneer or in the case of solid brick, you must ensure the wall plug goes deeper than the wall plaster. The wall plug needs a hole drilled for a good fit- not loose or the plug will rotate as you tighten the screw.

Side openning - you can adjust the curtain postion after installation by lifting the cord from its clip on the carriage and moving the carrier along to the correct position.
On one of the carrier slides there needs to be an overlap for the little carry bar for the curtain hooks so you do not get a gap when the curtain is shut.
When designing curtains there should be at least 2.5 drops ( window cobverage) for a good looking curtain.
To prevent heat loss thermo syphoning up the window, you should close in the pelmet on the top. Just 3 ply will do this fine.
For one side pull, you need to screw the cord pulley end to the floor or skirtin via the spring provided and set the length of cord by shortening at one of the carriage slides.
I may be rambling here, but a simple stud finder is really handy to find the studs (vertical timbers) It also shows power cables but they will not be as wide. Any photos of your house under construction is good to show where the timbers and power cables are.
It is a good idea not to hit the power cables - tends to burn things - like houses.
Anyway if you describe waht sort of fittings you have you may get more useful info.

I had this problem as well. The solution was to replace the 9 volt battery that it runs on. The beep was much louder and it calibrated correctly. Apparently the old battery was enough to make the beeping sound but not strong enough to emit the energy required to penetrate the drywall.

Never hang anything weighing more than 1/4 pound directly from plaster board. Purchase a "stud finder" from a hardware store. Use it to find a stud to support the weight.

I suspect there are several models but I have one model. 1) Turn on the unit (if the green light is blinking replace the battery). 2) Calibrate the unit by holding it flat against the wall for 5 seconds until the red light goes off and the beep stops. Make sure you do not move the unit during the calibration or position the unit over a stud (try a spot 6-12" away from the corner of the wall - most studs are on 16" or 24" centers and the wood/metal stud is 1 1/2" thick). If the unit keeps beeping or the red light doesn't go off during the calibration, move the unit sideways 5-8" in case you are above a water pipe or other reason for "too deep a surface" for the unit.

3) Do not lift the unit off the wall or you will need to recalibrate it. Slide the unit across the wall. When the upper red light comes on and the beeping starts, that marks one edge of the object in the wall (stud). Continue until the red light goes off and the beeping stops. Mark the other edge of the stud by moving the stud finder in the opposite direction and marking when the red light comes on and the beeping starts. The center of the two marks is the center of the stud for securing anything to the wall.

If the beep persists over a 6" range, I'd check if you have any old cast-iron pipes or a door/window that was relocated in that wall. Repeating the test in a few places vertically along that spot of the wall will tell you there is a consistent large object in that location. Neither a filled in window or door will run the entire length of the wall but you could be finding the headers (the vertical framing of the opening would probably be ~4-6" wide (double or triple stud depening on the needs of the house design)).

I hope this helps.

Cindy Wells
(on another stud-finder that I borrow, you press the buttons on the right and left side to turn it on. Calibrate by holding it to the wall for a short while and then slide it across the wall. Note when the top red led lights and the beep starts. Repeat in reverse to find the other side of the stud.)

The most common cause of failure in stud finders, with or without wiring detection, is a flat battery!
The lights may still work, the buzzer may still sound but at the end of the day it can take a bit of power to drive the oscillator/sensor circuitry. Replace the battery and try again.
If that doesn't work you may have a faulty unit: return it to the manufacturer because if you depend on it to tell you where live wires are, let alone finding the stud first time, it may cost more than just dollars!

usually you put it up against the wall between studs. Then you press a button and gradually move it left or right to find the studs in the wall.
If you initially have it pressed against the wall at a stud, it won't work right.