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#1 |
Registered Member
Join Date: Jan 2008
Posts: 55
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American Marine Pinpoint ph Owners/Experts
Having some calibration issues on a new monitor purchased on ebay. Please take the time to read.
I received a new kit. Probe had the calcium stuff around tip (normal i read), but there seemed to be a little dry cotton swab or filter floss type of stuff in the tip. Tip was not directly in swab and it did not appear that moist. Calibration 1: Cleaned probe with fresh water, inserted into #7 American marine buffer. Read something like 6.5 or 6.6. Tweaked this with the screw to 7. Cleaned probe, inserted into #10 Milwaukee buffer. Read something like 7.3 or 4. Tried to tweak the 4,10 screw and hit a wall around 7.7 or so and it would not go anymore. So I felt screwed and confused. Calibration 2: Cleaned probe in vinegar for a few hours. Inserted into #7 Milwaukee (kept consistent) and read 6.5, tweaked to 7. Cleaned and inserted into #10 Milwaukee and read 7.11. Tried to tweak higher and hit wall. More confused and angry. ------------------------------------- This does not seem right. It reads the #7 buffer within .5, but it 2.5 off for the #10 buffer. What am I doing wrong? or do I need to use American Marine only buffer solutions? or is this a faulty unit (can't understand if it read # fine). Any input appreciated. |
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#2 |
Registered Member
Join Date: Dec 2007
Location: Illisconsin
Posts: 172
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Buffer should be buffer, shouldn't matter what brand as long as it's clean, I like the singles instead of bottles. Maybe a bad probe, was it new or used. I would get a new probe and check worst case you'll have an extra probe. Sorry, not a big help.
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"Beer is living proof that God loves us and wants to see us happy." -Benjamin Franklin Current Tank Info: 125reef in progress, a few cichlid tanks |
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#3 |
Moved On
Join Date: Oct 2004
Posts: 6,847
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to start, insert the screwdriver and make sure both adjustment screws are in the middle of the range. do this by first turning the first screw <-- this way and then---> that way and figure out where the middle is. repeat on the next screw. then start the calibration. make sure you have the switch in the right position when you change screws during calibration.
also if your using the plug in adaptor this can cause interference and i would suggest not using it at all and just use the batteries |
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#4 | |
Registered Member
Join Date: Jan 2008
Posts: 55
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Quote:
what switch are you talking about? this may be what i am missing. i just see on/off and then a screw for 7 and screw for 4,10. i use 9v battery Last edited by themolt; 02/13/2008 at 09:48 PM. |
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#5 |
Moved On
Join Date: Oct 2004
Posts: 6,847
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i just grabbed my monitor and looked at it and i think i was confusing some things between the "monitor" and the "controller"
let me try again looking at my monitor, on the left below the lcd screen is the on/off switch. below that is the first screw with "7" next to it. below that is the second screw with "4 or 10" next to it. both these screws will turn about 2 or 3 times (2 or 3 full turns from start to finish)before bottoming out. what you need to do is find out where the middle point is before you start. the actual position of the screw does not determine the reading because every probe is different, that's why they can be turned so much. so start with the top screw that has the 7 next to it. turn it counter clock wise untill it stops. then turn it clock wise (counting how many full turns you make) untill it stops again. then divide the number of turns in half and that is the middle of the range. turn the screw until you are in the middle of the range. repeat on the second screw with 4 or 10 next to it. then turn the monitor on and start the calibration with the #7 solution and #7 screw. when you have it set at 7 rinse the probe and move to the #10 solution and #4 or #10 screw. keep going back and forth between the two solutions and screws untill both #'s are correct respectivly |
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#6 |
Registered Member
Join Date: Jan 2008
Posts: 55
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with nothing on, i can turn my screws 50 times or more either way. does not let me know when its bottomed out.
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#7 |
Moved On
Join Date: Oct 2004
Posts: 6,847
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to find the middle it doesnt matter. all you are doing is putting the screw in the middle so you have equal amount of turns both ways. don't even look at the LCD when doing this because it doesnt matter. you can turn the whole thing off and do it if you like
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#8 | |
Registered Member
Join Date: Jan 2008
Posts: 55
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Quote:
shouldn't the probe just pick up on the fact that the buffer solution is around 10, but not exactly. it certainly had 7 pretty close. i appreciate your advice though, but i think i will call American Marine tomorrow. |
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#9 |
Moved On
Join Date: Oct 2004
Posts: 6,847
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sent you a PM
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#10 |
Registered Member
Join Date: Jan 2008
Posts: 55
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sent one back.
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#11 |
Reef Chemist
![]() Join Date: Apr 2001
Location: Arlington, Massachusetts
Posts: 86,233
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Buffer should be buffer, shouldn't matter what brand as long as it's clean,
Almost true. Some brands are not accurate, unfortunately: A Comparison of pH Calibration Buffers http://reefkeeping.com/issues/2005-02/rhf/index.htm
__________________
Randy Holmes-Farley Current Tank Info: 120 mixed reef |
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#12 |
Reef Chemist
![]() Join Date: Apr 2001
Location: Arlington, Massachusetts
Posts: 86,233
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One good option is to call Lou Dell, the owner of American Marine. I'm sure he'll help figure out what is going on, which may include a broken probe.
Here's the contact info: http://www.americanmarineusa.com/company.html Tel. 800.925.4689 FAX 914.763.5367
__________________
Randy Holmes-Farley Current Tank Info: 120 mixed reef |
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