Hydrometer - Refractometer - Calibration, Reading

[bbearbrew]

Hi,
Could not find a thread that addressed my specific questions (sorry if there is one).
Apologize for long-winded post, but want to provide as much info as possible.

New to forum and brewing in general. I've brewed 6 batches (extract) at this point and trusted my hydrometer for measuing SG.
With last two started doing partial mash (steeping prior to that). As I've moved along I wanted to get better at taking my readings, measurements, etc. (to make OG adjustments post mash when adding extract to the boil).
To that point I acquired a refractometer. I assumed I could check/calibrate against my hydrometer (which I always assumed was accurate).
Reading on this and other forums I see that is not the case and you need to understand if there is a correction that is needed for both hydrometer and refractometer.

I found the following regarding calibration:
Using distilled water, take a reading with hydrometer (60 degrees) - should be 1.0
Mine read 1.0
Using same water I calibrated refractometer to read same
Found a "recipe" for calibrating - Prepare solution of 28 g table sugar and 176 g water and re-measure. Should be 1.048 SG
Hydrometer read 1.058
Refractometer read 1.055

Found another "recipe" for calibrating - 6 oz water and 1 oz sugar should yield 1.061 SG
Hydromoter read 1.071
Refractometer read 1.069

Note: when making the sugar solution I just added the sugar to the water and stirred until sugar was dissolved (no heat or anything).

At this point it seems that both the hydrometer and refractomoter are "off' only on the upper range by the same amount. It seems strange that "both" are off on the upper measurement by the same amount (0.010).

To be honest, I'm getting beffuddled by all the numbers and would appreciate any help I can get.
Did I calibrate correctly?
Am I worrying too much about .010 difference?

I then measured the brew I was doing (extract with steeping grains, no mashing):
Hydrometer - 1.070
Refractomoter - 1.067

Do I assume my actual OG is 1.060-1.057 (target gravity for the extract I brewed was 1.063)

While I do take RDWHAHB to heart would like to understand these basics before I move on. It may very well be this is the nature of the beast (accuracy of equipment) given these are not lab grade instruments.

Thanks for you thoughts, advice or guidance!

 

[RM-MN]

Your hydrometer are reading quite close for the sugar water, close enough for most purposes and to me that means they are accurate enough. The problem with taking an OG on an extract batch is that they usually use top off water and getting the concentrated wort mixed well with the top off water is very difficult which then leads the brewer into thinking there is a problem when that is not the case. Your hydrometer sample may have had a different concentration than the sample you took for the refractometer, I will advocate for just taking the expected OG as noted on the kit to be accurate. Use the hydrometer only for FG as the refractometer needs a correction for the difference that alcohol in the system causes.

When you start brewing all grain, the refractometer will be very handy as you can take a sample of hot wort to get an idea of the mash efficiency and make adjustments with water or extract if it is way off the expected. To do that with a hydrometer takes much more time as you need to chill that sample before inserting the hydrometer and each sample is a significant amount compared to the couple drops needed for the refractometer.

 

[bbearbrew]

Thanks for the response!
Regarding the "top off" there was no water added (I'm doing full boils).
The wort used on the refractometer was from the test jar I used when measuring with the hydrometer.