femtowatt | 1 fW | 2 fW | 3 fW | 4 fW | 5 fW | 6 fW | 7 fW | 8 fW | 9 fW | 10 fW | 11 fW | 12 fW | 13 fW | 14 fW | 15 fW | 16 fW | 17 fW | 18 fW | 19 fW | 20 fW | 21 fW | 22 fW | 23 fW | 24 fW | 25 fW | 26 fW | 27 fW | 28 fW | 29 fW | 30 fW | 31 fW | 32 fW | 33 fW | 34 fW | 35 fW | 36 fW | 37 fW | 38 fW | 39 fW | 40 fW | 41 fW | 42 fW | 43 fW | 44 fW | 45 fW | 46 fW | 47 fW | 48 fW | 49 fW | 50 fW | 51 fW | 52 fW | 53 fW | 54 fW | 55 fW | 56 fW | 57 fW | 58 fW | 59 fW | 60 fW | 61 fW | 62 fW | 63 fW | 64 fW | 65 fW | 66 fW | 67 fW | 68 fW | 69 fW | 70 fW | 71 fW | 72 fW | 73 fW | 74 fW | 75 fW | 76 fW | 77 fW | 78 fW | 79 fW | 80 fW | 81 fW | 82 fW | 83 fW | 84 fW | 85 fW | 86 fW | 87 fW | 88 fW | 89 fW | 90 fW | 91 fW | 92 fW | 93 fW | 94 fW | 95 fW | 96 fW | 97 fW | 98 fW | 99 fW | 100 fW |
ton of refrigeration (IT) | 2.8434512332475 × 10-19 TR | 5.6869024664949 × 10-19 TR | 8.5303536997424 × 10-19 TR | 1.137380493299 × 10-18 TR | 1.4217256166237 × 10-18 TR | 1.7060707399485 × 10-18 TR | 1.9904158632732 × 10-18 TR | 2.274760986598 × 10-18 TR | 2.5591061099227 × 10-18 TR | 2.8434512332475 × 10-18 TR | 3.1277963565722 × 10-18 TR | 3.4121414798969 × 10-18 TR | 3.6964866032217 × 10-18 TR | 3.9808317265464 × 10-18 TR | 4.2651768498712 × 10-18 TR | 4.5495219731959 × 10-18 TR | 4.8338670965207 × 10-18 TR | 5.1182122198454 × 10-18 TR | 5.4025573431702 × 10-18 TR | 5.6869024664949 × 10-18 TR | 5.9712475898196 × 10-18 TR | 6.2555927131444 × 10-18 TR | 6.5399378364691 × 10-18 TR | 6.8242829597939 × 10-18 TR | 7.1086280831186 × 10-18 TR | 7.3929732064434 × 10-18 TR | 7.6773183297681 × 10-18 TR | 7.9616634530929 × 10-18 TR | 8.2460085764176 × 10-18 TR | 8.5303536997424 × 10-18 TR | 8.8146988230671 × 10-18 TR | 9.0990439463918 × 10-18 TR | 9.3833890697166 × 10-18 TR | 9.6677341930413 × 10-18 TR | 9.9520793163661 × 10-18 TR | 1.0236424439691 × 10-17 TR | 1.0520769563016 × 10-17 TR | 1.080511468634 × 10-17 TR | 1.1089459809665 × 10-17 TR | 1.137380493299 × 10-17 TR | 1.1658150056315 × 10-17 TR | 1.1942495179639 × 10-17 TR | 1.2226840302964 × 10-17 TR | 1.2511185426289 × 10-17 TR | 1.2795530549614 × 10-17 TR | 1.3079875672938 × 10-17 TR | 1.3364220796263 × 10-17 TR | 1.3648565919588 × 10-17 TR | 1.3932911042913 × 10-17 TR | 1.4217256166237 × 10-17 TR | 1.4501601289562 × 10-17 TR | 1.4785946412887 × 10-17 TR | 1.5070291536211 × 10-17 TR | 1.5354636659536 × 10-17 TR | 1.5638981782861 × 10-17 TR | 1.5923326906186 × 10-17 TR | 1.620767202951 × 10-17 TR | 1.6492017152835 × 10-17 TR | 1.677636227616 × 10-17 TR | 1.7060707399485 × 10-17 TR | 1.7345052522809 × 10-17 TR | 1.7629397646134 × 10-17 TR | 1.7913742769459 × 10-17 TR | 1.8198087892784 × 10-17 TR | 1.8482433016108 × 10-17 TR | 1.8766778139433 × 10-17 TR | 1.9051123262758 × 10-17 TR | 1.9335468386083 × 10-17 TR | 1.9619813509407 × 10-17 TR | 1.9904158632732 × 10-17 TR | 2.0188503756057 × 10-17 TR | 2.0472848879382 × 10-17 TR | 2.0757194002706 × 10-17 TR | 2.1041539126031 × 10-17 TR | 2.1325884249356 × 10-17 TR | 2.1610229372681 × 10-17 TR | 2.1894574496005 × 10-17 TR | 2.217891961933 × 10-17 TR | 2.2463264742655 × 10-17 TR | 2.274760986598 × 10-17 TR | 2.3031954989304 × 10-17 TR | 2.3316300112629 × 10-17 TR | 2.3600645235954 × 10-17 TR | 2.3884990359279 × 10-17 TR | 2.4169335482603 × 10-17 TR | 2.4453680605928 × 10-17 TR | 2.4738025729253 × 10-17 TR | 2.5022370852578 × 10-17 TR | 2.5306715975902 × 10-17 TR | 2.5591061099227 × 10-17 TR | 2.5875406222552 × 10-17 TR | 2.6159751345877 × 10-17 TR | 2.6444096469201 × 10-17 TR | 2.6728441592526 × 10-17 TR | 2.7012786715851 × 10-17 TR | 2.7297131839176 × 10-17 TR | 2.75814769625 × 10-17 TR | 2.7865822085825 × 10-17 TR | 2.815016720915 × 10-17 TR | 2.8434512332475 × 10-17 TR |
The femtowatt (fW) is equal to one quadrillionth (10−15) of a watt. Technologically important powers that are measured in femtowatts are typically found in reference(s) to radio and radar receivers. For example, meaningful FM tuner performance figures for sensitivity, quieting and signal-to-noise require that the RF energy applied to the antenna input be specified. These input levels are often stated in dBf (decibels referenced to 1 femtowatt). This is 0.2739 microvolt across a 75-ohm load or 0.5477 microvolt across a 300-ohm load; the specification takes into account the RF input impedance of the tuner.
Name of unit | Symbol | Definition | Relation to SI units | Unit System |
---|---|---|---|---|
femtowatt | fW | = 10-15 W | = 10-15 W | Metric system SI |
femtowatts | tons of refrigeration (IT) | femtowatts | tons of refrigeration (IT) |
---|---|---|---|
1 | ≈ 2.8434512332475E-19 | 6 | ≈ 1.7060707399485E-18 |
2 | ≈ 5.6869024664949E-19 | 7 | ≈ 1.9904158632732E-18 |
3 | ≈ 8.5303536997424E-19 | 8 | ≈ 2.274760986598E-18 |
4 | ≈ 1.137380493299E-18 | 9 | ≈ 2.5591061099227E-18 |
5 | ≈ 1.4217256166237E-18 | 10 | ≈ 2.8434512332475E-18 |
A ton of refrigeration (TR), also called a refrigeration ton (RT), is a unit of power used in some countries (especially in North America) to describe the heat-extraction capacity of refrigeration and air conditioning equipment.
Name of unit | Symbol | Definition | Relation to SI units | Unit System |
---|---|---|---|---|
ton of refrigeration (IT) | TR | ≡ 2000 lb × iceIT / 24 h: iceIT = 144 °F × 2326 J/kg·°F | ≈ 3.516853×103 W | Imperial/US |
tons of refrigeration (IT) | femtowatts | tons of refrigeration (IT) | femtowatts |
---|---|---|---|
1 | ≈ 3.516853E+18 | 6 | ≈ 2.1101118E+19 |
2 | ≈ 7.033706E+18 | 7 | ≈ 2.4617971E+19 |
3 | ≈ 1.0550559E+19 | 8 | ≈ 2.8134824E+19 |
4 | ≈ 1.4067412E+19 | 9 | ≈ 3.1651677E+19 |
5 | ≈ 1.7584265E+19 | 10 | ≈ 3.516853E+19 |
femtowatts | tons of refrigeration (IT) |
---|---|
1 | ≈ 2.8434512332475 × 10-19 |
3.516853 × 1018 | ≈ 1 |
Symbol | Definition |
---|---|
≡ | exactly equal |
≈ | approximately equal to |
= | equal to |
digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |