Retro Review: Halo HLC-1 Lighting Calculator
|HLC-1 Lighting Calculator|
Type: 4-Function, Lighting
Memory Registers: 1 (M)
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.
|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:
Room Width in feet, [ RW ]
Rood Length in feet, [ RL ]
Room Cavity Height in feet, [ H ]
[ 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)
Coefficient of Utilization, between 0 and 1, [ CU ]
Number of lamp lumens, [ LL ]
Required footcandles, [ FC ]
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 ] ).
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.
This blog is property of Edward Shore, 2017