FX-120i, FX-200i, FX-300i Problems

[T-shooter]

As far as I know all these scales are the same except the maximum weight limit. I'm having fits with my FZX-300i. I read the entire posts from "USMCDOC" and have tried almost everything. I have it in a small room, no air currents, solid wood table not touhing the wall. Also, an anti-static pad and wrist strap, a Tripp Isobar outlet, a grounding wire on the back of the scale, an anti-vibration pad, a couple cheap ferrite units on the power cord and sprayed everything down with Static Guard. I just ordered 2 more from Old-Will-Knott-Scales. I keep the temperature and humidity constant and leave it turned on.

Sometimes the scale is perfect. I weighed over 100 times using 3 different items and it read exactly every time except once. I lifted the pan off and reweighed it 10X more and it never varied. Other times this thing has a mind of it's own. Some things I've noticed are:

* Sometimes after calibrating, the weight used will weigh 1 division more or less every time.

* When the lid is removed, usually the weight is 1 to 2 divisions low, replace the lid, and it returns. I've sprayed the entire breeze shield (except the clear panels) with Static Guard spray.

* Sometimes it's rock solid, sometimes it drifts up and/or down by 1 to 2 divisions after a couple minutes.

* When it wants to act up, changing the settings doesn't help, Zero Tracking, Condition, or Stability.
* I've turned off everything electrical in the house except the scale and it doesn't matter. I'm not near a cell tower and there are no electrical line withing 50 yards of the house except the main line in.

* Even zeroing it out between weighings doesn't always eliminate the drift.

I did notice on day when the weather was changing as a storm came in, the scale was drifting badly. I also did a heat test. When the temp goes up, the reading drops, cool makes it increase. I ran the temp in the room from 50 to 90 degrees when testing. The scale doesn't seem to be bothered by vibrations. I can pound on the desktop and it usually doesn't react. It does seem sensitive to static. With everything connected and all grounded to earth ground, sometimes I'll reach to it and the reading will move a little. Usually takes a while for that to repeat like the static slowly builds up over a few minutes time.

For the expense of this scale, I want to see the same reading near 100% of the time and be able to depend on it. I hope there is something I'm overlooking. My only option may be to get a priest to do an exorcism in case it, or me, is possessed.

 

[coford]

The only thing that seems to mess with my FX120I is humidity. Don't know why but when the humidity is low the scale may drift up or down .01+- but when the humidity is 50% or more there is no drift.

 

[dkhunt14]

I don't believe any scale is going to weigh exact 100 percent of the time. A grain is 1/7000 of a pound and now read to .01 of that and it is a pretty small number. Then you have to throw in the repeatability and accuracy of the scale. When only reading in numbers that end in 2 if it is close to the midddle it can drift up and down a .01.

I have noticed with all electronic scales if you weigh early in the morning or late at night they weigh better. I believe voltage is more consistent because less electricity is being used. It can also be some kind of interference. I also noticed if you set the scale on a granite slab it seems to help dampen vibrations and works better. You might need a line conditioner. Matt

 

[BrushyHillGuide]

If you've got to do all those things, like turning off all the electronics in the house, to get your scale to work I'd be looking for a different scale. My $125 Gempro250 doesn't drift like what you're describing. My ES's are usually in the single digits and always below the upper 'teens' with it. It's plugged into a power strip and I keep my phone away from it; but it sits next to my Chargemaster

If I were having the issues you're having, it'd be going in for repair or a refund.

 

[T-shooter]

The only thing that seems to mess with my FX120I is humidity. Don't know why but when the humidity is low the scale may drift up or down .01+- but when the humidity is 50% or more there is no drift.

It could be somewhat due to humidity. Humidity is relative to the temperature. By turning on the heat in my loading room, the weight reading went from 49.998g to 50.006g (grams). I shut the heat off and it dropped back down again. I'm going to try and stabilize the temp higher and lower for a few hours and see if I can figure what it's doing. Hot air is more thin and has less weight. If I can keep the scale from drifting, it seems to weigh accurately. I'm using a weight to check the drift, not zero which tends to stay in one place.

 

[T-shooter]

I don't believe any scale is going to weigh exact 100 percent of the time. A grain is 1/7000 of a pound and now read to .01 of that and it is a pretty small number. Then you have to throw in the repeatability and accuracy of the scale. When only reading in numbers that end in 2 if it is close to the midddle it can drift up and down a .01.

I have noticed with all electronic scales if you weigh early in the morning or late at night they weigh better. I believe voltage is more consistent because less electricity is being used. It can also be some kind of interference. I also noticed if you set the scale on a granite slab it seems to help dampen vibrations and works better. You might need a line conditioner. Matt

I've noticed the scales weigh better especially late at night. It would be the electric or possibly the environmental conditions are more stable, not heating/cooling because of the sun. The repeatibility when I checked it is with the exact same weight. I see what you mean about being on the threshold.

 

[T-shooter]

If you've got to do all those things, like turning off all the electronics in the house, to get your scale to work I'd be looking for a different scale. My $125 Gempro250 doesn't drift like what you're describing. My ES's are usually in the single digits and always below the upper 'teens' with it. It's plugged into a power strip and I keep my phone away from it; but it sits next to my Chargemaster

If I were having the issues you're having, it'd be going in for repair or a refund.

I've had two GemPro-300's They had their issues. Both would weigh to +/- .02 grains 95% of the time. I weighed 4 items alternating them, over 100 separate weighings, and The GemPro only went over twice by .02 and under once by .02 grain. So most were in a .04 range. It would also weigh 1 kernel of Varget as long as the pan was removed and set back down again. It would start reading at 3 kernels at .06 and go from there. I weighed from 3 through 25 , and added 25 more for a total of 50. The last scale rarely needed zeroed. The first needed to be zeroed every time to be accurate.

But for 4X the price, I expect a little more from this scale. It will read 1 kernel of Varget and you can trickle 1 at a time and it reads each one. If I can get the drifting issue to stop, I'll be more than happy.

 

[powderbrake]

Welcome to the world of high gain electronics. If you really need the accuracy, then you have to treat it like it's a laboratory device, and completely control it's environment. I doubt if the accuracy, linearity, repeatability and temperature sensitivity and line voltage conditions are fully specified, nor do I believe the home reloader can verify them. Nor do I believe a home reloader can control the environment as necessary to not see drift.

4.998 to 50.006 grams is a change of .016% .008 grains. Ill bet the interior volume of any two cases are not identical to within .008 grains of water.

 

[spclark]

T-shooter you may be onto something with the exorcism thing.

Maybe your house is built on an old graveyard?

Or an underground river?

Or a meteor's buried a few feet below your reloading room?

I've had five electronic scales of various brands, none have given me the fits you've been living thru. My FX-120i (about a year old now) is the best of 'em all.

Wish I had some ideas for how to get yours working but you named everything I know to try & some I'd not yet heard of too.

 

[ED3]

It could be somewhat due to humidity. Humidity is relative to the temperature. By turning on the heat in my loading room, the weight reading went from 49.998g to 50.006g (grams). I shut the heat off and it dropped back down again. I'm going to try and stabilize the temp higher and lower for a few hours and see if I can figure what it's doing. Hot air is more thin and has less weight. If I can keep the scale from drifting, it seems to weigh accurately. I'm using a weight to check the drift, not zero which tends to stay in one place.

“...When the lid is removed, usually the weight is 1 to 2 divisions low, replace the lid, and it returns….”
“...I shut the heat off and it dropped back down again….”

The first thing that occurs to me is air currents from a forced air HVAC system.

"Hot air is more thin and has less weight.”
… not exactly...
A pound of hot air weighs the same as a pound of cold air...
Warm is is less dense than cold air, as is humid air, and the air during a low barometric pressure episode.
A cubic foot of warm, or humid, or low pressure air, weighs less than the same volume of cool, dry, higher (barometric) pressure air.
Were air density an issue, humidity changes (humid air being less dense than dry air), and weather frontal passages- low pressure to high pressure, and vice-versa, would have similar effects….

I'd look at air currents in the room.

Good Luck, and keep us posted.

 

[dskogman]

If it is a power issue you should really use a small UPS. The surge protector has some some filtering but a UPS is much more isolated. You can even pull the plug and run off battery for a while to go off the grid.

https://www.amazon.com/gp/product/B000ANF8FO/?tag=accuratescom-20

 

[Twoboxer]

You have said you have no air currents, and you say the temp and humidity are constant enough. You say you are grounded . . . can't do a lot better than all that.

So let me repeat a story when I first set up my FX120i.

I had an incandescent pole lamp positioned over my left shoulder to provide task lighting. One of the cones of light was of course directed at the scale. The scale would remain perfectly stable . . . until I moved my hand toward it to place a pan. At that point it would start "fluttering".

If I turned off the light, that didn't happen. My own theory was that the air was warmed in the area of the scale and when my hand entered that space the air column was disturbed. Removed the incandescent, went to LEDs, no problem now.

Dunno if that's your problem . . . or one of them . . . but at this point it seemed worth typing out again.

 

[fgregorio]

Just think that the power cord of your power supply is like a powerful antenna. It will have currents inducted into it from ANY electromagnetic field or source around it, including your mobile phone. Any frequency will induct.
Also inside your house, the socket power supply will vary, depending on demand and the EM fields generated by your home appliances.
If you can, use battery power. It will only vary one way (weaker over time at a slow change rate). Same applies to the EM field surrounding said batteries for which the scale can easily calibrate against accurately.

 

[T-shooter]

Welcome to the world of high gain electronics. If you really need the accuracy, then you have to treat it like it's a laboratory device, and completely control it's environment. I doubt if the accuracy, linearity, repeatability and temperature sensitivity and line voltage conditions are fully specified, nor do I believe the home reloader can verify them. Nor do I believe a home reloader can control the environment as necessary to not see drift.

4.998 to 50.006 grams is a change of .016% .008 grains. Ill bet the interior volume of any two cases are not identical to within .008 grains of water.

I agree 100%. I try to control the environment the scale is in as much as possible but there is only so much that can be done. I've had 3 other scales. 2 of them could be run off an internal battery. Neither changed how they acted when run off a battery or line voltage. I believe it's better to control everything you can while reloading even though perfection doesn't exist in the real world.

 

[T-shooter]

T-shooter you may be onto something with the exorcism thing.

Maybe your house is built on an old graveyard?

Or an underground river?

Or a meteor's buried a few feet below your reloading room?

I've had five electronic scales of various brands, none have given me the fits you've been living thru. My FX-120i (about a year old now) is the best of 'em all.

Wish I had some ideas for how to get yours working but you named everything I know to try & some I'd not yet heard of too.

You may be on to something. I never thought about it before but we have had more than a normal amount of lightning strikes within 250-300 yards averaging about 1 per year over the last 20 years. I've seen lightning strike the ground several times and burn a hole in the grass. There could be a large iron deposit under ground. I've also had 5 (4 different ones) that would weigh to .001 gram (.02 grain). Each one would occasionally be rock stable, and other times be unstable no matter how hard I tried to control the environment in the room I load in.

 

[T-shooter]

“...When the lid is removed, usually the weight is 1 to 2 divisions low, replace the lid, and it returns….”
“...I shut the heat off and it dropped back down again….”

The first thing that occurs to me is air currents from a forced air HVAC system.

"Hot air is more thin and has less weight.”
… not exactly...
A pound of hot air weighs the same as a pound of cold air...
Warm is is less dense than cold air, as is humid air, and the air during a low barometric pressure episode.
A cubic foot of warm, or humid, or low pressure air, weighs less than the same volume of cool, dry, higher (barometric) pressure air.
Were air density an issue, humidity changes (humid air being less dense than dry air), and weather frontal passages- low pressure to high pressure, and vice-versa, would have similar effects….

I'd look at air currents in the room.

Good Luck, and keep us posted.

The small room I reload in had an electric baseboard heater so no forced air. It is turned off for a while before I try to reload. Air currents do caused the scale to be very unstable so I try to block them as much as I can. . I have noticed problems when the outside conditions are rapidly changing like when a storm front approaching. I can deal with that. I meant to say that warmer air had less weight per volume that cool air.

 

[jlow]

One small disadvantage of the FX-120i I have over the GemPro 250 is it is much more sensitive to any wind.

The reason is simple, it has a larger weighting surface and so more surface for the wind to push down on. The wind screen is good to block wind from the outside assuming it is coming from the direction it is blocking, but if you have three wind screen up and one open and the top partially blocked off (this is the configuration I use when running the FX-120i in conjunction with the autotrickler), if wind comes from the direction of the open port, it will stall inside the balance and push down on it causing drift.

This does not have to be due to a fan or the furnace but could be if you approach the balance fast (your body is like a huge sail...) or even wave you hand in front of the open port. This is not to say that this is a significant problem as I normally sit in front of the balance and do not run around it or wave my hand, but it is something to be aware of. You are basically dealing with a very sensitive instrument and so yes it detects a lot of stuff that we normally take for granted.

 

[T-shooter]

I agree 100%. I try to control the environment the scale is in as much as possible but there is only so much that can be done. I've had 3 other scales. 2 of them could be run off an internal battery. Neither changed how they acted when run off a battery or line voltage. I believe it's better to control everything you can while reloading even though perfection doesn't exist in the real world.

Meant to say I had 3 similar scales. I also tried a magnetic force restoration balance that would weigh to .0001 gram and it displayed similar issues actually being worse because it was so sensitive and could not get a reliable weight with the breeze shield open even a little. One of the others was a $300 strain gauge scale and it was by far worse than any of the others regardless of the settings. Something else I've just noticed is that the readout will drop 1 increment instantly when I get close to it and go back as soon as I move again. Even though the pad, scale, and wrist strap are all grounded to earth ground through the house electric. It only effects in the front and left side and is much more sensitive if I lay my arm up close vs just a finger (larger body mass). It seems to do this when the weight is maybe half way in between readings. It the readout drifts a little more (slowly drifting) it doesn't respond to this for a while. I tried a small magnet near the scale in the same areas and it's not affected by it.

 

[T-shooter]

One small disadvantage of the FX-120i I have over the GemPro 250 is it is much more sensitive to any wind.

The reason is simple, it has a larger weighting surface and so more surface for the wind to push down on. The wind screen is good to block wind from the outside assuming it is coming from the direction it is blocking, but if you have three wind screen up and one open and the top partially blocked off (this is the configuration I use when running the FX-120i in conjunction with the autotrickler), if wind comes from the direction of the open port, it will stall inside the balance and push down on it causing drift.

This does not have to be due to a fan or the furnace but could be if you approach the balance fast (your body is like a huge sail...) or even wave you hand in front of the open port. This is not to say that this is a significant problem as I normally sit in front of the balance and do not run around it or wave my hand, but it is something to be aware of. You are basically dealing with a very sensitive instrument and so yes it detects a lot of stuff that we normally take for granted.

I've been thing about trying to reduce the weighing surface area. Like you said, I think it too large and that could be a lot of the problems. The inner platform (pan support) could easily be cut down since it looks like chrome plated plastic and it has a ridge under it measuring 2.4" If I can find a stainless cover (weighing pan) for it that fits, it may be an improvement. I use the Dandy/Omega trickler and only leave one panel out when reloading.

 

[dkhunt14]

You may be on to something. I never thought about it before but we have had more than a normal amount of lightning strikes within 250-300 yards averaging about 1 per year over the last 20 years. I've seen lightning strike the ground several times and burn a hole in the grass. There could be a large iron deposit under ground. I've also had 5 (4 different ones) that would weigh to .001 gram (.02 grain). Each one would occasionally be rock stable, and other times be unstable no matter how hard I tried to control the environment in the room I load in.

I would definitely put a surge protector on it. Some of the good ones like showed in the above link will pay for damages of a lightning strike or surge, plus it will help with line voltage. Good insurance for an expensive investment. Matt