Retro Review: Halo HLC-1 Lighting Calculator
 |
| HLC-1 Lighting Calculator |
Years: Unknown
Type: 4-Function, Lighting
Memory
Registers: 1 (M)
Battery: A76
The Halo HCL-1
is a professional lighting calculator and a standard 4-function calculator. The
standard 4-function calculator should be self-explanatory, let’s focus on the lighting
part.
The HCL-1 is
abundant on eBay, and make sure you get it with the foldout manual because (1)
the manual is well written and (2) it explains the process in which pre-programmed
calculations are completed. I will show
a short summary of some of the pre-calculations available below.
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| Trig table from the manual, something we don't see in calculator manuals |
Did I mention
that the manual contains a short table of sines and cosines?
US units are
used (length is measured in feet).
Calculating Room Cavity Ratio:
Input:
Room Width in
feet, [ RW ]
Rood Length in
feet, [ RL ]
Room Cavity
Height in feet, [ H ]
Output:
[ RCR ]
calculates the Room Cavity Ratio
The HCL-1
assumes a rectangular room. The formula:
RCR = (5 * H *
(RW + RL)) / (RW * RL)
(Source: https://algonline.org/index.php?gloss&glossaryid=232&glossarytitle=Room+Cavity+Ratio+(RCR
, Advanced Lighting Guidelines web site)
Footcandle
Calculation
Input:
Coefficient of Utilization,
between 0 and 1, [ CU ]
Number of lamp
lumens, [ LL ]
Required
footcandles, [ FC ]
Output:
Press [ CAL
]. If successful, a 0 appears in the display.
[ RCL ] [ NUM
]: number of adjusted luminaries
(lights)
[ RCL ] [ FC
]: number of adjusted footcandles
[ RCL ] [ A
]: area that is illuminated
[ RCL ] [ SPG
]: fixture spacing in feet
I am thinking
that this solves where to put ceiling lights on the ceiling in a grid, like in
a school classroom or business office.
You can factor
in the lamp lumen depreciation factor ( [ LLD ] ) AND luminaire dirt
deprecation factor ( [ LDD ] ).
Final Verdict
I am glad to
have the HLC 1 in my collection. It is
one of the most unique calculators ever made and was met with amusement when I
posted a picture of it on my Instagram account.
Don’t lose the manual.
Eddie
This blog is
property of Edward Shore, 2017