Fundet via søgning på Google.
PPM is a calculation of EC or CF.
CF= EC multiplied by 10. ex, 1.0ec x 10 = 10CF
EC = CF divided by 10. ex, 10CF divided by 10 = 1.0 EC
The problem with ppm is that its not a standardized way of taking readings so almost every product manufacture has a different way of measuring ppm. in other words thier ppm conversion factor.
a .7 factor is actually called a 442 conversion factor wich is approximately 700 multiplied by EC.
a .5 factor or the NaCl conversion factor wich is approximately 500 multiplied by EC.
Depending on wich type of TDS meter you use it will use either a .5 or .7 conversion factor. this is why some people get different readings with different meters.
Lets say your nutreint solution was 1.0 EC
using the .7 conversion factor your PPM would be 700.
using the .5 conversion factor your PPM would be 500.
Heres a conversion chart:
(EC)------(PPM.5)---------(PPM.7)-------(CF)
.4---------200-------------280-----------4-----Seedling/ rooted clones
.6---------300-------------420-----------6-----
.8---------400-------------560-----------8-----Veg
1.0--------500-------------700----------10
1.2--------600-------------840----------12
1.4--------700-------------980----------14
1.6--------800-------------1120---------16-----Aggressive
1.8--------900-------------1260---------18
2.0--------1000------------1400---------20-----Super aggressive
2.2--------1100------------1540---------22
2.4--------1200------------1680---------24-----Be carefull after this point!!
2.8--------1400------------1960---------28
3.2--------1600------------2240---------32
3.6--------1800------------2520---------36
4.0--------2000------------2800---------40
4.4--------2200------------3080---------44
Dog vil jeg sige, at det ikke er så "farligt" at bevæge sig op til ja 3,0 - 4,0 men det afhænger af sorten.
Lidt mere, samligning af kendte mærker af måleudstyr.
MoS 