pH color match

[Hachu]

Hi. I am having a hard time trying to figure out my pH level. Which pH level do you see in these pictures? I'm using Taylor k2006c test kit with recommended 5 drops of R-0004.

 

[mknauss]

7.5-7.6

 

[Texas Splash]

What you use as a background can really impact the shades. While many like a white background, it doesn't seem to help me personally. My house siding is an off-white almost beige color, so that, combined with good outside indirect lighting helps me distinguish those shades when it get close to the upper 7s.

 

[Hachu]

I tried all different background ( off white brick wall, the sky, natural light behind me, towards the natural light, white paper) and that was the most consistent color I can get m, and still unsure what that is. I was thinking 7.7, but mknauss thinks 7.5-7.6 ..that makes a big difference on my csi level.

I ran into someone else's post and said to use 4 drops and it looks like 7.8 to me, but not sure if I should even go by that since it is not what recommended by the kit.

 

[Texas Splash]

We all can see the shades slightly different, especially via phone or laptop. I thought it was more closer to 7.8-8.0, but it's tough online.

 

[mknauss]

I look at color, not shade. With 5 drops of reagent the shade is always too intense for me. 4 drops of reagent makes it much easier, for me, to decipher the scale.
I would not get real concerned over a pH from 7.5 to 7.7. CSI is not that perfect and all of this is a bit like hand grenade throwing. Close is good.

 

[HermanTX]

Many of us use the TF-100 test kit and that includes a K-1000 comparator. The range on that is only 5 levels - 6.8, 7.2, 7.5, 7.8, 8.2
So as stated in another post - being close is good enough.

 

[Dirk]

I use 4 drops. I can't really make 5 drops work. This is my process for picking the color. You can skip some of these steps as you get better at it.

First, I work indoors, so I can get consistent results. I can't rely on outdoor light for that. I hold the comparator below an under-counter LED light strip. In the other hand I hold a white card 3 or 4" behind the comparator, at an angle between the comparator and the light source, sort of reflecting the LED light off the card through the squares of the comparator. If I'm having trouble with the color matching, I might alter the angle a bit to help.

I start at the bottom (though from the top works, too). I look at the 7.0 color, and then the color of the sample right next to it. I ignore all but those two squares. I ask myself, is the sample "oranger" or "pinker" than the 7.0 square. In your example, it's pinker. I move up to 7.2, the sample is still pinker. 7.4? Sample is still pinker. 7.6? Getting close, but the sample is still just a tiny bit pinker. This is where I might tweak the card's angle a bit, to confirm that. Then I look at 7.8. The sample is very close, maybe just a hair more orange. I double check by going to 8.0, the sample is definitely oranger than 8.0. So... pinker than 7.6, Oranger than 8.0. Tiny bit oranger than 7.8. I would conclude 7.7.

Say it was pinker than 7.6, but I couldn't call it for 7.8, and it was oranger than 8.0. Then I'd go with 7.8. For some reason, judging each color one at a time like that, without looking at the whole scale, not even the adjacent squares above or below, works for me.

In your picture, had you used 4 drops, this MO would have been even easier.

 

[Dirk]

If you're worried about the test's viability using four drops, it's easy enough to do both. Put in four drops. Determine the match. Then put in the fifth drop and go again. You'll likely end up with the same result...

 

[Hachu]

I use 4 drops. I can't really make 5 drops work. This is my process for picking the color. You can skip some of these steps as you get better at it.

First, I work indoors, so I can get consistent results. I can't rely on outdoor light for that. I hold the comparator below an under-counter LED light strip. In the other hand I hold a white card 3 or 4" behind the comparator, at an angle between the comparator and the light source, sort of reflecting the LED light off the card through the squares of the comparator. If I'm having trouble with the color matching, I might alter the angle a bit to help.

I start at the bottom (though from the top works, too). I look at the 7.0 color, and then the color of the sample right next to it. I ignore all but those two squares. I ask myself, is the sample "oranger" or "pinker" than the 7.0 square. In your example, it's pinker. I move up to 7.2, the sample is still pinker. 7.4? Sample is still pinker. 7.6? Getting close, but the sample is still just a tiny bit pinker. This is where I might tweak the card's angle a bit, to confirm that. Then I look at 7.8. The sample is very close, maybe just a hair more orange. I double check by going to 8.0, the sample is definitely oranger than 8.0. So... pinker than 7.6, Oranger than 8.0. Tiny bit oranger than 7.8. I would conclude 7.7.

Say it was pinker than 7.6, but I couldn't call it for 7.8, and it was oranger than 8.0. Then I'd go with 7.8. For some reason, judging each color one at a time like that, without looking at the whole scale, not even the adjacent squares above or below, works for me.

In your picture, had you used 4 drops, this MO would have been even easier.

Thank you for responding. I will try your technique since I do have LED undercounter. for my sample, 4 drops was very easy to tell..it was 7.8. Unfortunately, that picture resolution was too big and I couldn't post it.