How and why do you use your HP calc?

[Neve]

(09-14-2017 08:42 PM)Csaba Tizedes Wrote:  

(09-14-2017 01:32 PM)Neve Wrote:  What model are you using? What do you use it for, could you be more specific?

I'm a mechanical engineer - mainly fluid flow and process engineer. Our company (EWB Ltd.) works on ash handling technology field of power plant industry. My task is design process and preparing our solutions from scratch to contract signing (technically and partially financially).

Therefore during my work mainly stands lots of fluid flow calculations (eg. pressure drop on a pipeline during pneumatic conveying of various materials), lots of static calculations (loads on steel structures, pipe bridge's loads, loads on silo walls, silo tops, effect of earthquake, wind, etc...), equipment selection (direct selection from well known companies products or just estimating motor power requirements, selecting instrumentation, selecting vessel sizes, silo dimensions, unloading equipments under silos, compressors, blowers, dust filters, etc...).

Sometimes we have offering slurry systems, in this case same as above, but the material is high density slurry and we are using pumps instead of compressors.

Of course mainly we do the above on PC, but many little part of this procedure simply to calculate on a pocket calculator. For example if you must to select dust filter area, you can use "thumb rules" and you can estimate it with a calculator.

When I was a student (that was 1999~2004), I used a 15C, a 32SII and a 48SX. I have preferred my 32SII (because it was smaller than 48SX and have alpha LCD and EQN list which was better than 15C).

During years I noticed that for my design work no need to write long programs, only required to use a good solver. So my selection was a 35S, which is during a battery replacement deleted everything - so I trade it for something and I started to test many another calculator (the full TI83/84/89/TINspire line, old CASIOs, new CASIOs, HP 48GX, 49G, 48GII) - and it seems to me, my 32SII is the best, but I must to back to 35S again (because I have ~30-40 equations and ~4-5 little programs which is required for my job).

So my selection is a 35S, but I hate ->P and ->R is missing, and to start a program why we need to give the line number?!?! And yes, the greatest fault: why only one character variable names? Why - at least - one character + one number and we can write easily the Bernoulli equation - and many more.

And what about the weekends and free time? I prefer to use what I want: I have some CASIO, I like to play with them. I really like my fx-50F, this is the best well designed little calculator. I wrote on it many little programs (because it has 29 steps memory only).

I try to share stuffs in our Calculator Group (Calculator Google Group - Hungary), for example a short story about how to use SOLVE + indirect addressing on HP15C: Down to the Rabbit hole, a short article about the night sky temperature and freezing on a surface: Night sky temperature, and a story how I beloved to my dead 12C and how I prepared on it a SOLVE(i): SOLVE with indirect addressing on 12C.

So, you can guess, why I prefer mostly HP calculators.

Csaba

Very nice!
Yes, I do understand.
I've never owned any real calculators but an older HP41C (circa early 1980) bought in 1985, and another HP41CX 20 years ago that was stolen last year. Just bought another one that I'm actually waiting to arrive in the mail.
I also bought a HP50g 4 years ago, thinking it would be nice replacement and/or upgrade to the venerable 41. But, although a very nice calculator, a replacement it is not.