Just got a hannah phep ph meter , set it up and did 2 point
calibration with pre packaged buffers....7 and 4.01 according to
dorections.after calibration is "locked in" , i tested some tap
water , then both buffers...the 4.01 tested just that , but the 7
tested like 7.3 . is this normal deviation ?

On Sep 15, 6:47 am, wrote:
Just got a hannah phep ph meter , set it up and did 2 point
calibration with pre packaged buffers....7 and 4.01 according to
dorections.after calibration is "locked in" , i tested some tap
water , then both buffers...the 4.01 tested just that , but the 7
tested like 7.3 . is this normal deviation ?

No, unless it's a 'checker'. The prpbe on that meter is not very
stable in my experience. Most Hanna meters have an accuracy (or
precision) of 0.1 pH or better. Recalibrate it and see if it works
better.

The pHep5 has an annoying habit of shutting down through an auto time;
if it powers off you need to recalibrate it. There is a work
around. Just press hold. It keeps it up several minutes longer. I
wrote a pH meter FAQ a while ago, just search the archives or i can
repost.

Joe

Also,

If it is a new meter the probe was probably dry.

The readings are more stable after the probe has been hydrated



Joe Sallustio wrote:
On Sep 15, 6:47 am, wrote:
Just got a hannah phep ph meter , set it up and did 2 point
calibration with pre packaged buffers....7 and 4.01 according to
dorections.after calibration is "locked in" , i tested some tap
water , then both buffers...the 4.01 tested just that , but the 7
tested like 7.3 . is this normal deviation ?

No, unless it's a 'checker'. The prpbe on that meter is not very
stable in my experience. Most Hanna meters have an accuracy (or
precision) of 0.1 pH or better. Recalibrate it and see if it works
better.

The pHep5 has an annoying habit of shutting down through an auto time;
if it powers off you need to recalibrate it. There is a work
around. Just press hold. It keeps it up several minutes longer. I
wrote a pH meter FAQ a while ago, just search the archives or i can
repost.

Joe

I would add that, in my experience with my Hannah meter, it is
important to keep the sensor stored in appropriate storage solution.

I've also found that if the meter gets a little flaky, soaking it for
30 minutes in storage solution, then re-calibrating helps. It often
requires two successive two-point calibrations to get it accurate.


In article
wrote:
Also,

If it is a new meter the probe was probably dry.

The readings are more stable after the probe has been hydrated




--
I'm using an evaluation license of nemo since 113 days.
You should really try it!
http://www.malcom-mac.com/nemo

On Sep 15, 7:42 am, Joe Sallustio wrote:
On Sep 15, 6:47 am, wrote:

Just got a hannah phep ph meter , set it up and did 2 point
calibration with pre packaged buffers....7 and 4.01 according to
dorections.after calibration is "locked in" , i tested some tap
water , then both buffers...the 4.01 tested just that , but the 7
tested like 7.3 . is this normal deviation ?

No, unless it's a 'checker'. The prpbe on that meter is not very
stable in my experience. Most Hanna meters have an accuracy (or
precision) of 0.1 pH or better. Recalibrate it and see if it works
better.

The pHep5 has an annoying habit of shutting down through an auto time;
if it powers off you need to recalibrate it. There is a work
around. Just press hold. It keeps it up several minutes longer. I
wrote a pH meter FAQ a while ago, just search the archives or i can
repost.

Joe

The guy at grape and granary said this meter wouldn't need calibrated
each time I use it...is this accurate?

Must be a different Hannah than any I've used. Mine needs calibrating
on any day I intend to use it - if I expect the readings to be
accurate.


In article
. comtheodore.lowe@gma
il.com wrote:


The guy at grape and granary said this meter wouldn't need
calibratedeach time I use it...is this accurate?


--
I'm using an evaluation license of nemo since 113 days.
You should really try it!
http://www.malcom-mac.com/nemo

I actually calibrate mine twice before using.
And I calibrate it everyday I plan on using it.



AxisOfBeagles wrote:
Must be a different Hannah than any I've used. Mine needs calibrating
on any day I intend to use it - if I expect the readings to be
accurate.


In article
. comtheodore.lowe@gma
il.com wrote:


The guy at grape and granary said this meter wouldn't need
calibratedeach time I use it...is this accurate?

On Sep 16, 6:23 am, wrote:
On Sep 15, 7:42 am, Joe Sallustio wrote:





On Sep 15, 6:47 am, wrote:

Just got a hannah phep ph meter , set it up and did 2 point
calibration with pre packaged buffers....7 and 4.01 according to
dorections.after calibration is "locked in" , i tested some tap
water , then both buffers...the 4.01 tested just that , but the 7
tested like 7.3 . is this normal deviation ?

No, unless it's a 'checker'. The prpbe on that meter is not very
stable in my experience. Most Hanna meters have an accuracy (or
precision) of 0.1 pH or better. Recalibrate it and see if it works
better.

The pHep5 has an annoying habit of shutting down through an auto time;
if it powers off you need to recalibrate it. There is a work
around. Just press hold. It keeps it up several minutes longer. I
wrote a pH meter FAQ a while ago, just search the archives or i can
repost.

Joe

The guy at grape and granary said this meter wouldn't need calibrated
each time I use it...is this accurate?- Hide quoted text -

- Show quoted text -

No, it's not accurate. You are really calibrating the probe, not the
meter. You need to get the offset and slope set right for the
readings to mean anything. The pH7 buffer sets the offset and the pH
4 sets the slope.