HP41/42 Unit Conversion



#2

The recent thread on 50g Unit Conversions reminded me just how awesome the 48 and 50 unit support is.

So, what do you all use for the 41 and 42? Any good programs/modules for unit conversion?

Thanks.


#3

I'm not sure but one of the ROM's has a built in unit conversion. It might be the petroleum pack, but I'm not 100% sure.


#4

It is in the Petroleum Pack (ROM), and in the Thermal Transport ROM too. The unit conversions slightly differ - no-no, not in the conversion factors, sure - but in the number of units for conversion.

Ciao.....Mike

#5

(Albeit limited) unit conversions on the keyboard -- one of the few things that the 32sii has over the 42s and the 41.


#6

I dunno, but it seems to me that the whole issue is a waste of calculator memory. I just memorized (years ago) the conversion constants for the conversions I used frequently, then just "did the math" on my HP when i needed a conversion. When I need another conversion, I just memorize a new constant - I have WAY more memory than the calculator! Fer instance (from memory) 1 US Survey Foot is 0.30480060960 meters, 1 International Foot is 0.304800000 meters, the coefficient of expansion of steel is 0.00000654 units per unit per degree Fahrenheit, the value of PI is 3.14159265358979323846264338327950288419716939937510582097
4944592307816406286208998628034825342117067..., etc. (OK, I fudged a little on that last one >;o) I DO know it to 12 places though!)

#7

The 41C/42S are known "scientific" calculators. In science, almost no unit conversions are needed - some physical constants are more important. I can explain the reasons if you want to ;-)


#8

Walter: 100% agree!

#9

User assigned keys, for specific work applications, but no built in conversions to speak of:

Key 1:     quick calculations to convert U.S. gallons (as boarded
in the States) of JET A fuel into Kilograms for
comparison to onboard guages calibrated in Kilo's.
(using standard day temperature as a quick reference)
Key 2: quick calculations to convert litres(as boarded in
the everywhere else!) of JET A fuel into Kilograms for
comparison to onboard guages calibrated in Kilo's(using
standard day temperature as a quick reference).
Keys 4, 5: Meters to feet and feet to meters, for airspace altitude
confirmation with altimeter calibrated in feet. China,
Russia and Mongolia to name a few.
Keys 7, 8: Inches of mercury to Millibars and vice versa. Used at
the flight planning computer which always shows data in
inches of mercury, whereas, most European and Asian
airports give air pressure in Millibars/hPa.
Keys ., 0 the ubiquitous requirement for Celsius to Farenheit and
back!

Cheers, Geoff


#10

Hi!

And what is the "AIRCANADA" key doing?

Greetings, Max


#11

Appeasing the politically correct at the company?

;-)

Cheers,

I know I have asked before but I get 3 day layovers in Mainz. Any chance of a beer, if I give you enough notice?


#12

Hi!

Quote:
I know I have asked before but I get 3 day layovers in Mainz. Any chance of a beer, if I give you enough notice?

Of course! Some years ago, I helped out a (now defunct) company based in Mainz by flying their Cessna 421s every now and then - so I should still be find the way. But in view of the beers, I would rather take the train (it's a 2 1/2 hour trip)...

Looking forward to it,
Max

#13

Hi, Geoff --

Key 1 and Key 2 may have been helpful in the 1983 "Gimli Glider" incident.

-- KS


#14

Your right on that, but unfortunately they did not have the correct measurements from the maintenance drip!

The drip sticks were in inches, converted to pounds in the manual, which had to be back converted to metric kilograms for the guages.

A dog's breakfast, so to speak. Compoumd that with unserviceable cockpit totalizers and fuel guages, a bad MEL book explanation, new equipment to the company (B767) and you can see the " Swiss Cheese " accident waiting to happen.

I think the fuel was metered by the fueler in gallons no less.

In a nut shell:

gallons - inches - pounds - liters - kilograms.

Each step completed by a differing department with no onboard confirmation or procedure due to a bad MEL.


I always do an independent check of the fuel using the two keys depending on the departure requirements/ I never rely on the onboard system for the complete answer.

Cheers, Geoff

Edited: 28 Mar 2009, 9:05 p.m.

#15

Hi Geoff,

what's that "PHONE" function on the + key in user mode?

cheers,

hpnut in Malaysia


#16

Hello Hpnut!

The phone, code, keys are programs with attached data bases. A primitive PIM in fact which I created before PDA's.

Phone key initiates the prompt "Contact?" By inputting at least the first 3 letters of the phone number you want to see you get the completed number as well as the completed name. The name and number reside in the X-memory.

Codes are the door codes for access to the ramp at various airports. Place the correct airport identifier in the alpha register after the prompt "AIRPORT?" and you get the code.

The WP-A key works the same way. Press the key and you get the prompt "AIRPORT?". Enter any 3 letter airport code; SYD for Sydney, Australia. Get a second "AIRPORT?" prompt and enter the second airport code in; YVR for Vancouver. The result is the Initial True Track and Great Circle distance between the Airports. This is because the Lat and Lon of each Airport is stored in x-memory with the airport code tagged to it.

Cheers, Geoff

#17

The HP 41 Thermal and Transport Science module added unit conversion capability to the 41. As I recall, you would place the number you wanted to convert into the X register and into the alpha register the string of units you wanted to convert from - to. ("ft*lbf/s - BTU/hr") and then hit a "convert" function.

Unit checking/conversion was built into all the programs on it as well. If you opted for "Units" when running the program, then after prompting for the value, it would prompt for the units, which you would enter as an alpha string. It gave instructions for incorporating this capability into your own programs. As a chemical engineering major, this ROM was worth more than its weight in gold to me. The Petrloleum Engineering PAC also included this capability.


#18

The Machine Design Pac for the 41C series also has a similar unit conversion capability.

1. You key in the unit string in the Alpha register (it has a virtually unlimited set of unit conversions due to the ability to combine unit control characters *, /, -, and 1-9 with unit strings and equations).

2. Key in the numeric value to be converted

3. The program is executed with either FCON for forward conversion or BCON of backward conversion using the same unit conversion string.

I find this program very handy and often more convenient for complex units than the RPL models - as long as you assign FCON and BCON to keys! I am amazed at the number of conversions that are possible using this program.

Jeff

#19

This thread reminds me of another item on my "ToDo list" - namely adding electrical units to the unit conversion libraries, as implemented on the different 41 modules... which I always found a very elegant and effective way to do it.

With 82 units built-in, the Petroleum ROM has the more complete set, followed by the Thermal ROM (54) and the Machine ROM (42). Some are unique to one module but many are present on more than one. There are a "grand total" of 87 different units amongst the three.

Here below are listed, FWIW - not that this adds any useful data to this subject though.

Best,
ÁM

ACRE acre
ANG angstrom
API Degree API
ATM Atmosphere
BAR Bar
BBL Barrel of petroleum
BCF Billion Cubic Feet of Gas
BTU British Thermal Unit
C Degree Celsius
CAL Calorie
CM Centimeter
CP Centipoise
CST Centistoke
D Darcy
DAY Day
DYNE Dyne
ERG Erg
F Degree Farenheit
FT Foot
FTH2O Foot of Water
G Gram
GAL Gallon (US)
GALUK Gallon (UK)
HP Horsepower
HR Hour (mean solar)
IN Inch
INHG Inch of Mercury
INH2O Inch of Water
J Joule
K Kelvin
KCAL kilocalorie
KG Kilogram
KGF Kilogram Force
KIP Kilopound Force
KJ Kilojoule
KM kilometer
KMOL kilomole
KPA kilopascal
KSI KIP per square inch
KT kilotonne
KW kilowatt
L liter
LBF pound force
LBM pound mass
M meter
MBAR milibar
MCF thousand cubit feet gas
MD millidarcy
MG megagram
MI mile
MIC micron
MIL 1/1000 inch
MIN minute
MJ megajoule
ML milliliter
MM millimeter
MMCF million cubic feet gas
MMHG millimiter of mercury
MN meganewton
MO month
MOL(E) mole
MPA megapascal
MT megatonne
MW megawatt
N newton
P(OISE) poise
PA pascal
PDL poundal
PSF pound force per square foot
PSI pound force per square inch
R degree rankine
S second
SCF standard cubic foot
SCM standard cubic meter
SCMZ standard cubic meter 2
SLUG slug
SPGR specific gravity to water
ST(OKE) stoke
T tonne
THERM 10^5 BTU
TON short ton
TONUK long ton
TORR torr
UM micrometer
W watt
YD yard
YR year
OHM Ohm
A Ampere
V Volt
FD Farad
HY Henry
TES Tesla
GAUS Gauss
CUL Culombe
PFAD Pico Farad
MHY Millihenry


#20

In your list are different sets of units. FWIW I tried to put some structure in:

ACRE acre            >IMP<
ANG angstrom = 10^-10 M
API Degree API
ATM Atmosphere >OUTDATED<
BAR Bar >OUTDATED<
BBL Barrel of petroleum >IMP<
BCF Billion Cubic Feet of Gas >IMP<
BTU British Thermal Unit >IMP<
C Degree Celsius
CAL Calorie >OUTDATED<
CM Centimeter = 1/100 M
CP Centipoise = 1/100 POISE
CST Centistoke = 1/100 STOKE
D Darcy >IMP<
DAY Day = 24 * 3600 S
DYNE Dyne >OUTDATED<
ERG Erg >OUTDATED<
F Degree Farenheit >IMP<
FT Foot >IMP<
FTH2O Foot of Water >IMP<
G Gram = 1/1000 KG
GAL Gallon (US) >IMP<
GALUK Gallon (UK) >IMP<
HP Horsepower >IMP<
HR Hour (mean solar) = 3600 S
IN Inch >IMP<
INHG Inch of Mercury >IMP<
INH2O Inch of Water >IMP<
J Joule >SI<
K Kelvin >SI<
KCAL kilocalorie = 1000 CAL
KG Kilogram >SI BASE<
KGF Kilogram Force >OUTDATED<
KIP Kilopound Force >OUTDATED<
KJ Kilojoule = 1000 J
KM kilometer = 1000 M
KMOL kilomole = 1000 MOLE
KPA kilopascal = 1000 PA
KSI KIP per square inch >IMP<
KT kilotonne = 1000 TONNE
KW kilowatt = 1000 W
L liter = 1/1000 CBM
LBF pound force >IMP<
LBM pound mass >IMP<
M meter >SI BASE<
MBAR milibar = 1/1000 BAR
MCF thousand cubit feet gas >IMP<
MD millidarcy = 1/1000 D
MG megagram = 1 million GRAM
MI mile >IMP<
MIC micron >IMP<
MIL 1/1000 inch >IMP<
MIN minute = 60 S
MJ megajoule = 1 million J
ML milliliter = 1/1000 L
MM millimeter = 1/1000 M
MMCF million cubic feet gas >IMP<
MMHG millimiter of mercury >IMP<
MN meganewton = 1 million N
MO month
MOL(E) mole >SI<
MPA megapascal = 1 million PA
MT megatonne = 1 million TONNE
MW megawatt = 1 million W
N newton >SI<
P(OISE) poise >SI<
PA pascal >SI<
PDL poundal >IMP<
PSF pound force per square foot >IMP<
PSI pound force per square inch >IMP<
R degree rankine
S second >SI BASE<
SCF standard cubic foot >IMP<
SCM standard cubic meter
SCMZ standard cubic meter 2
SLUG slug >IMP<
SPGR specific gravity to water
ST(OKE) stoke >SI<
T tonne = 1000 KG
THERM 10^5 BTU >IMP<
TON short ton >IMP<
TONUK long ton >IMP<
TORR torr >OUTDATED<
UM micrometer = 10^-6 M
W watt >SI<
YD yard >IMP<
YR year = 365,2425 DAY
OHM Ohm >SI<
A Ampere >SI BASE<
V Volt >SI<
FD Farad >SI<
HY Henry >SI<
TES Tesla >SI<
GAUS Gauss >OUTDATED<
CUL Culombe >SI<
PFAD Pico Farad = 10^-12 FD
MHY Millihenry = 1/1000 HY

One can cut down this list massively by just taking into account the known meanings of milli, mega, kilo, centi etc. Units like ERG and DYN were already outdated when I studied some 35 years ago. Etc.

Edited: 31 Mar 2009, 10:30 a.m.


#21

They may be "outdated" but sure enough are on the modules. Not sure that such a thing exist, anyway: units are units... they'll always be.

Best,
AM

Edited: 3 Apr 2009, 5:52 a.m.


#22

When you take old modules, you'll get old units. Quite naturally.

#23

Quote:
So, what do you all use for the 41 and 42?
Just write tiny programs for the conversions you use and assign them to keys. One I use sometimes that's probably not in any module is wire diameter to wire guage and vice versa. Another is musical note to frequency and vice-versa.

Edited: 28 Mar 2009, 8:12 p.m.

#24

There is a Feet-Inches-Fractions Calculator for the HP-41CX here.

© 1984 by Fred E. Lusk III, PE

He alludes to "creating an HP-42S version, but never got around to finishing".

Any thoughts on how hard would it be to modify this program to work on the 42s?


#25

There is an HP 48S/G type unit conversion program for the Hp 42S on Thomas Okken's web site. I have thought about adding to it to make it more like the 48 version, but have not found the time to study what is being done in the program to add to it.


#26

The unit conversions in the Machine Design Pac (FCON, BCON), Petroleum Fluids Pac (CON, INCON), and the Thermal & Transport Science Pac (SI-, -SI) are all machine language functions, which makes it a bit of a pain to port them.

I'm interested in adding some sort of unit conversion functionality to Free42; could someone point me to a list of officially sanctioned conversion factors?

Note: for those of you who use Palm PDAs, there is a neat unit conversion utility called YAUC (as in Yet Another Unit Converter). It's not supported but I think it is still floating around on the 'net here and there. I use it regularly for U.S./SI conversions; it has a ton of units, but it doesn't deal with compound units like the RPL calculators do (or the above 41 pacs). Still, worth a mention.


#27

You might look here:

http://physics.nist.gov/Document/sp811.pdf

See appendix B.8 (p.45 ff.)

There may be more help here:

http://www.bipm.org/en/si/conversions.html


#28

That's perfect, thanks!!


#29

Thomas,

So are you thinking of a non-42S functional enhancement to Free42? An evolution of the 42S? If so, I applaud your effort, and will formally ask for another enhancement: 41CX Time function support. How sweet, the 42SX!

Thanks.

Edited: 3 Apr 2009, 5:59 p.m.


#30

Hi Egan!

That sounds like a good addition -- I'll put it on my list.


The one I'm *really* looking forward to adding is iPhone accelerometer access. :-)

- Thomas


#31

Quote:
The one I'm *really* looking forward to adding is iPhone accelerometer access.

Is this really an accelerometer or is it just a position switch?

#32

Yes, it is a 3 axis accelerometer.

#33

So there is a wish list? I'd add displaying flags 0-4 as in 41 and fraction input as in HP35s.

Cheers


#34

Hmm, well, I can add those to my to-do list, but whether they will get done any time any time soon is another matter. The problem with fractions is that that requires adding a new data type, and that affects just about everything. Huge, huge amount of work. You're probably better off using a 50g instead.


Adding annunciators to the display is a lot easier, but it will require changes to all the skins. At least those changes are a lot easier than the changes that would be needed to support a 4-line display...


#35

Thanks Thomas, well I sort of guessed so but could not resist to mention it. Never mind.
Cheers and keep up the good work!
Reth

#36

I've always liked this site.

Not so much for accuracy as the comprehensive nature of weird units :-)

- Pauli

#37

Martin....

It's still on my "to-do" list :-(

Actually, several years ago I nearly completed the re-write for the 41CX version that I mention in the program description. I just haven't had time to do the last bit of checking, polishing, and documenting. The new version will more easily port to the 42S than the original because of reduced reliance on XFUNCTIONS. However, a new granddaughter and other things in life have pushed this back on the priority list.

I don't do FIF calculations that much anymore, but for day-to-day use I wrote an Excel spreadsheet that allows me to enter as many dimensions as I need. The spreadsheet includes a multiplier for each dimension so I can do things like x*A + y*B ...

One of these days....

Fred


#38

Quote:
© 1984 by Fred E. Lusk III, PE

It's still on my "to-do" list :-(


Fred,

Wow, you are worse than me... will I live long enough to make a dent in my To Do List?

I still need to do FIF calculations frequently. I regularly just do them by first mentally converting to decimal feet, if precision is not so important. Or if it is, I use the 32sii fraction mode for the inches, then convert back to feet. Now that I finally obtained a 42s, I would like to make use of its power with a program that like the one you wrote.

Of course, if I was really practical, I would just buy a Calculated Industries calculator. But it wouldn't be an HP...

Anyway, thanks for responding, that was a nice surprise.


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