Table I
Operating characteristics and radiation output of four mercury lamps.
Lamp Cooper Hewitt Type H-1 Type H-2 Type H-3
Inside tube diameter (cm) 2.4 3.5 2.5 .4 Arc length (cm) 128 16.0 10.5 1.8 Vapor pressure (atm) .0003 1.4 .4 28.5 Volts 71.9 150 67.5 251 Amp. 3.70 2.77 4.06 .401 Watts* 266 400 250 85.6 Lumens 6500 16000 7000 3400 Lumens per watt* 24.5 40 28 39.5 Candles per mm2 † .031 1.4 1.0 18
Principal Lines Band of Wave-lengths Spectral Intensities (μw per cm 2 at One Meter Distance from Lamp Axis )
17100–16900 34.4 11.9 6.9 15300 27.1 7.9 6.1 13955–13570 44 14.8 8.5 12100–11900 27.4 8.2 6.3 11289 35.7 12.5 7.8 10140 34.3 69 22.7 10.8 7420–6830 3.3 3.75 6830–6350 5.7 2.3 3.0 6350–5950 5.6 1.9 3.1 5791–5770 5950–5615 26.3 127 55 19.2 5461 5615–5320 81 131 57.5 33.5 5320–5060 3.5 1.24 2.2 5060–4840 3.02 1.47 2.05 4840–4650 .63 2.2 4650–4475 .62 2.6 4358 82 92 44.5 27.1 4047 59 44.5 23.6 14.5 3663–3650 30 41 22.5 25.7 3341 2.7 3.2 3129 15 6.9 3022 .28 1.21 2967 .10 .73
* Exclusive of losses in auxiliary equipment.
† Maximum value at center of arc.
Table II
Operating characteristics and percentage of input radiated in various ultra violet lines for a bare capillary arc tube and a bare Uviarc.
Inside Tube Diameter (cm ) Arc Length (cm ) Vapor Pressure (atm .) Volts Amp . Watts *
Bare capillary-tube .4 1.8 28.5 250 .403 85.6 d.c. Uviarc for 110v line 1.5 8.5 1.0 75 3.75 281
Percent of Input Radiated in Spectral Lines Wave-length Bare capillary tube d.c. Uviarc for 110v line 3663–3650 2.85 3.66 3341 .40 .27 3132–3126 1.73 2.53 3027–3021 .76 1.12 2967 .68 .55 2925 .19 .068 2894 .30 .20 2806–2803 .31 .39 2753 .24 .123 2701–2697 .23 .164 2655–2652 .37 .83 2537–2535 .064 1.14 2484–2482 .14 .33 2464 .065 .052 2447 .031 .043 2401–2399 .063 .142 2380–2378 .079 .128 2353 .089 .076 2323 .085 .047 2302 .084 .076 2259 .039 .048 Erythemal U.V.† 1.92 2.82 Erythemal U.V. of λ’s>2800A 1.38 1.37 Erythemal U.V. of λ’s<2800A .54 1.45
* For arc tube only.
† Equivalent of λ2967A for producing a “minimum perceptible erythema.”
Table III
Operating characteristics and spectral distribution of visible radiation for a water-cooled capillary arc tube.
Inside Tube Diam . (cm ) Arc Length (cm ) Vapor Pressure (atm ) Volts Amp . Watts * Lumens L /W Candles per mm 2 †
.2 1.2 110 505 1.35 580 38,200 66 445
Band of Wave -lengths Intensities ‡ 7250–6960 42 6960–6705 41 6705–6470 38 6470–6245 40 6245–6045 45 6045–5865 67 5865–5690 125 5690–5535 114 5535–5390 197 5390–5250 47 5250–5123 34 5123–5000 35 5000–4890 46 4890–4790 57 4790–4695 56 4695–4605 52 4605–4515 62 4515–4430 90 4395–4320 150 4280–4210 68 4210–4140 62 4080–4020 105 4020–3960 42 3960–3900 38
* For arc tube only.
† Maximum value at center of arc.
‡ μw per cm
2 at one meter from arc axis.
Table IV
Percentage of total light from mercury arcs operating at various pressures, from sun and from a tungsten lamp which is of wave-lengths 6000–7600A.
Source Mercury Pressure (Atm .) Percent of Light 6000–7600A H-1 lamp 1.4 1.0 H-2 lamp .4 .6 H-3 lamp 28.5 1.9 Water-cooled capillary arc 110 7.0 Sun 20.0 500 watt, 115 volt tungsten lamp 27.0