Yesterday I spoke to Les at Durite about my concerns and today 29th May spoke to Mellisa who is sending an email to Les with directions to this page.
a) there is difficulty in viewing the thermometer liquid, being red doesn't help as that is also the background colour of the container shedding red light eveyrwhere. It appears as though the thermometer is skewed by some 20 to 30 degrees. It can't be adjusted :(
b) After my earlier conversation I noted the scale is high by about 2 points, to resolve that I cut a small strip off the removable scale insert to set it lower.
Here are images of the issue a)
1. I slipped a small peice of a plastic bag behind the thermometer to contrast the background and block any red relfection. You can see the red liquid is just about visible when looking directly at it.
2. When viewing from the right about 30° the liquid is clearly visible.
3. With the scale reinserted and looking at it straight on
4. With scale inserted and looking from 20°
- I have labeled the two S6 145s A and B
and the cells in each are respectively (neg to pos), (pos to neg) ~ 1,2,3
Specific Gravity Readings
May 12th just before sunset.
A1 = 1.280 :: A2 = 1.275 :: A3 = 1.250 | B1 =1.280 :: B2 = 1.275 :: B3 = 1.260
This was before charging and I broke the hydrometer when cleaning so couldn't check the SG during or after charging which aslo included an automatic equalisation.
May 28th Mid afternoon when on float
A1 = 1.290 :: A2 = 1.292 :: A3 = 1.292 | B1 =1.292 :: B2 = 1.292 :: B3 = 1.260
The new Durite 472 has a thermometer for temp coefficients and although it was difficult to read it appears as though at least 6 points should be added, i.e. 1.290 becomes 1.296.
I spoke to Scotty at Durite who said SG's should be within 1%, i.e. 1.290 &plusmin; .0129 (0.013) so a range of 1.277 to 1.303 or 0.26 max diff.
Update: May 28th 2020
Received the Durite 472. It's larger than I thought but usuable. The liquid in the thermometer is red as is the surround so it's difficult to read the temp.Spoke to a guy at tech 01255 555200 for over half an hour ~ details should be appended ~ Need to make a nice box for it.
Update: May 23rd 2020
I broke the glass containers on both the hydrometers mentioned below and have bought a premium claibrated (0.002) sg @ some £54. A Durite model 472 It has a range of 1.22 to 1.3 so the scale will also be larger than the previous buys.
I have ended up buying two hydrometers. I first called Plymouth Battery Centre who informed me they had a glass model at £19 which I thought was a bit expensive so when I went to town I thought I'd look around before I took the mile or more walk to Prince Rock.
The Toolshed could get a glass model for £5 and the car shop next door had the same model for £2.99, which I bought. When I went to the Plymouth Battery Centre to buy some red and black covered multi-core cable I decided to buy the hydrometer they had anyway, which cost £14.50 eventually.
The better model from Plymouth battery Centre is the one on the left, although you cannot see the coloured scale. It is supplied by Gordon Equipments under the name DURITE model 0-070-00 ; range 1.15 to 1.40; accuracy 0.01. All parts are individually replaceable.
Concerns regarding the cheapo
- The float diameter is much smaller than the container diameter so the readings are at an angle.
- On the side of the container the float rests, the surface tension of the acid draws the liquid further up the side of both, giving a distorted view.
- The scale is on the small side so not so easy to read.
- And of course there's the idea that the calibration is off.