aced126
Bluelighter
- Joined
- May 18, 2015
- Messages
- 1,047
Here is an idea I thought of in order to measure accurate quantities of a solid in the range of 10mg if the scale you have access to is not really accurate or safe for measuring doses under about 1000mg. The idea is based on the fact that a suitably crushed solid powder will have a nearly constant density at all points in the powder.
Note that this is in the interest of harm reduction. You should use this method only when you really need to. To further reduce the chances of something going wrong, one needs to use a scale appropriately accurate to the dosage.
The gist of it is that you take a known volume container which fills a very small amount of powder (say 20mg of powder). Fill it up completely and then empty out the powder of the filled container elsewhere. Repeat until all the powder has been filled and emptied, and take note of how many times you had to use the volume container. If say you used it 200 times to completely fill 1000mg, then you know that your container will be able to dose 5mg.
So one needs to simply divide the original mass of the solid by the number of times the container was used to obtain the mass capacity of the container.
This allows for accurate and safe dosing when an accurate scale is inaccessible.
Since this works on the principle that volume is directly proportional to mass given the density is constant, one needs to try to keep the density as constant as possible while it is in the container. This means that while filling the container, one needs to keep the process of filling the container the same each time.
For example, if you were using a cigarette paper with a filter pushed down slightly (giving a small cylindrical volume), then you would need to either compress the powder each time with the same amount of force, or don't compress it at all each time. You could "half compress" it but this is not practical at all as you would not be able to apply a constant force each time.
Note that you do need to know the starting mass of the solid. This cannot be determined simply by the mass the dealer claims it to be. Even research chemicals sometimes contain 2 times as much mass as ordered.
I'm not too sure where to post this, but I think it could be a good harm reduction strategy for those who do not wish to purchase a scale. There is small possibility of calculation error of course, so one must repeat the calculation a few times to ensure no mistakes have been made.
The advantage with this is that depending on how small and appropriate your container is, you could be even more accurate than high accuracy scales, although it is of my personal opinion that I strongly recommend against high potency drugs (dosage<10mg) anyway as too much can and does go wrong. In the 100-300mg range is much more benign to mistakes in measuring doses.
Additional more technical stuff:
The biggest error will for sure be in the fluctuations of powder density in each filling of the container. Mathematically speaking, I calculated the % error range of the mass that the container is capable of storing as :
mass in container = mass weighed/number of times container used
% error = plusminus ((absolute uncertainty of total mass of solid/total mass) + (2*absolute uncertainty in density/density))*100
If we do a sample calculation and have the following parameters: total mass=2000mg, absolute uncertainty of total mass = plusminus 100mg (if the scale is accurate to say 0.1g, this would be the case), we used a container that filled up 100 times until it had filled the entire mass, so number of times container used = 100. We don't know the density of the powder, but if we account for quite a large fluctuation of density change while filling up the container and assume the % uncertainty in density is 10%, then that implies absolute uncertainty in density/density = 0.1
If we apply all these numerical values to the equations we obtain:
Mass weighed each time by cylinder = 20mg
% error = 25%
So each dose measured by the cylinder is 20mg plusminus 25%
That means each dose will be in between 15 and 25mg.
15mg < dose (20mg) <25mg
Note how we've essentially turned a scale with an accuracy of 0.1g into an accuracy of 0.001g. Nevertheless, in the interest of harm reduction it is safer to use a proper scale. Use this only when absolutely necessary.
Obviously yeah, there's quite a big difference in 15 and 25mg, but it will likely not mean really fatal events occuring as a result of unmeasured dose. Some people might argue that you can eyeball within that dosage range accurately anyway. I disagree because 1) not all compounds have the same density and 2) while under the influence mistakes in eyeballing are way more likely to occur.
Note that this is in the interest of harm reduction. You should use this method only when you really need to. To further reduce the chances of something going wrong, one needs to use a scale appropriately accurate to the dosage.
The gist of it is that you take a known volume container which fills a very small amount of powder (say 20mg of powder). Fill it up completely and then empty out the powder of the filled container elsewhere. Repeat until all the powder has been filled and emptied, and take note of how many times you had to use the volume container. If say you used it 200 times to completely fill 1000mg, then you know that your container will be able to dose 5mg.
So one needs to simply divide the original mass of the solid by the number of times the container was used to obtain the mass capacity of the container.
This allows for accurate and safe dosing when an accurate scale is inaccessible.
Since this works on the principle that volume is directly proportional to mass given the density is constant, one needs to try to keep the density as constant as possible while it is in the container. This means that while filling the container, one needs to keep the process of filling the container the same each time.
For example, if you were using a cigarette paper with a filter pushed down slightly (giving a small cylindrical volume), then you would need to either compress the powder each time with the same amount of force, or don't compress it at all each time. You could "half compress" it but this is not practical at all as you would not be able to apply a constant force each time.
Note that you do need to know the starting mass of the solid. This cannot be determined simply by the mass the dealer claims it to be. Even research chemicals sometimes contain 2 times as much mass as ordered.
I'm not too sure where to post this, but I think it could be a good harm reduction strategy for those who do not wish to purchase a scale. There is small possibility of calculation error of course, so one must repeat the calculation a few times to ensure no mistakes have been made.
The advantage with this is that depending on how small and appropriate your container is, you could be even more accurate than high accuracy scales, although it is of my personal opinion that I strongly recommend against high potency drugs (dosage<10mg) anyway as too much can and does go wrong. In the 100-300mg range is much more benign to mistakes in measuring doses.
Additional more technical stuff:
The biggest error will for sure be in the fluctuations of powder density in each filling of the container. Mathematically speaking, I calculated the % error range of the mass that the container is capable of storing as :
mass in container = mass weighed/number of times container used
% error = plusminus ((absolute uncertainty of total mass of solid/total mass) + (2*absolute uncertainty in density/density))*100
If we do a sample calculation and have the following parameters: total mass=2000mg, absolute uncertainty of total mass = plusminus 100mg (if the scale is accurate to say 0.1g, this would be the case), we used a container that filled up 100 times until it had filled the entire mass, so number of times container used = 100. We don't know the density of the powder, but if we account for quite a large fluctuation of density change while filling up the container and assume the % uncertainty in density is 10%, then that implies absolute uncertainty in density/density = 0.1
If we apply all these numerical values to the equations we obtain:
Mass weighed each time by cylinder = 20mg
% error = 25%
So each dose measured by the cylinder is 20mg plusminus 25%
That means each dose will be in between 15 and 25mg.
15mg < dose (20mg) <25mg
Note how we've essentially turned a scale with an accuracy of 0.1g into an accuracy of 0.001g. Nevertheless, in the interest of harm reduction it is safer to use a proper scale. Use this only when absolutely necessary.
Obviously yeah, there's quite a big difference in 15 and 25mg, but it will likely not mean really fatal events occuring as a result of unmeasured dose. Some people might argue that you can eyeball within that dosage range accurately anyway. I disagree because 1) not all compounds have the same density and 2) while under the influence mistakes in eyeballing are way more likely to occur.
