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Physical Measurement Laboratory / Sensor Science Division

Fluid Metrology Group

Index of Semiconductor Process Gases - Helium

HELIUM-4

M.W. [1]

4.0026

N.B.P [2]

4.224 K

T.P

N/A

Pc [2]

0.2275 MPa

Tc [2]

5.2 K

Vc [3]

0.057475 m³/kmol

Note: In the tables, # is used for properties obtained from estimation methods. * and + are used to distinguish between differing data sets within a single column. If no uncertainty is specified, then no uncertainty was provided by the reference.

T K	$$ \frac{C_P^0(T)} {R} $$	Vapor Pressure MPa	B(T) cm³· mol^-1	dB/dT·T cm³· mol^-1	C(T) cm⁶· mol^-2	dC/dT·T cm⁶· mol^-2	λ mW/ (m·K)	η µPa·s
Estimated Uncertainty	-	-	1%	-	10%	-	0.1%	0.1%
Reference	-	-	4	4	5	5	4	4
100	2.5	-	11.636	2.114	115.30	95.88	74.8	9.6
120	2.5	-	11.944	1.288	126.64	33.54	84.4	10.8
140	2.5	-	12.096	0.692	129.07	0.37	93.4	11.9
160	2.5	-	12.157	0.242	127.78	-18.31	102.1	13.0
180	2.5	-	12.165	-0.109	124.95	-29.15	110.4	14.1
200	2.5	-	12.138	-0.390	121.52	-35.51	118.5	15.1
225	2.5	-	10.076	-0.671	117.06	-39.80	128.2	16.4
250	2.5	-	11.993	-0.896	112.75	-41.76	137.7	17.6
273.15	2.5	-	11.906	-1.066	109.01	-42.36	146.2	18.7
275	2.5	-	11.899	-1.078	108.73	-42.37	146.9	18.8
300	2.5	-	11.798	-1.229	105.04	-42.22	155.9	19.9
325	2.5	-	11.695	-1.356	101.69	-41.60	164.6	21.0
350	2.5	-	11.590	-1.464	98.63	-40.73	173.2	22.1
375	2.5	-	11.486	-1.556	95.86	-39.71	181.6	23.2
400	2.5	-	11.383	-1.636	93.33	-38.62	189.9	24.3
450	2.5	-	11.182	-1.767	88.91	-36.39	206.0	26.3
500	2.5	-	10.990	-1.868	85.19	-34.23	221.7	28.3
600	2.5	-	10.636	-2.013	79.30	-30.38	251.9	32.2
700	2.5	-	10.318	-2.108	74.87	-27.18	280.9	35.9
800	2.5	-	10.032	-2.174	71.42	-24.52	308.9	39.5
900	2.5	-	9.773	-2.219	68.66	-22.31	336.1	43.0
1000	2.5	-	9.538	-2.251	66.41	-20.45	362.6	46.4
1200	2.5	-	9.124	-2.288	62.95	-17.51	413.9	52.9
1400	2.5	-	8.769	-2.306	60.43	-15.29	463.3	59.3
1600	2.5	-	8.461	-2.310	58.50	-13.57	511.3	65.4
1800	2.5	-	8.189	-2.308	56.99	-12.19	558.1	71.4
2000	2.5	-	7.946	-2.300	55.76	-11.06	603.9	77.3
2500	2.5	-	7.436	-2.271	53.53	-8.98	714.8	91.5
3000	2.5	-	7.025	-2.236	52.03	-7.56	821.9	105.2
3500	2.5	-	6.683	-2.200	50.95	-6.52	926.0	118.6
4000	2.5	-	6.392	-2.164	50.13	-5.74	1027.8	131.6
4500	2.5	-	6.139	-2.129	49.49	-5.12	1127.8	144.4
5000	2.5	-	5.916	-2.096	48.98	-4.62	1226.3	157.1
6000	2.5	-	5.540	-2.034	48.20	-3.87	1419.6	181.8
7000	2.5	-	5.230	-1.979	47.65	-3.33	1609.3	206.2
8000	2.5	-	4.969	-1.929	47.23	-2.92	1796.3	230.2
9000	2.5	-	4.745	-1.883	46.91	-2.60	1981.2	253.9
10000	2.5	-	4.549	-1.841	46.65	-2.35	2164.6	277.4

References:

IUPAC, "Atomic Weights of the Elements 1993," J. Phys. Chem. Ref. Data (1995, 24, 1561).
Ho, C.Y. and Touloukian, Y.S., 1981 Properties of Nonmetallic Fluid Elements," (1981, McGraw-Hill Book Co., New York).
"Selected Values of Properties of Chemical Compounds," Data Project; Thermodynamics Research Center, Texas A&M University, College Station, TX (1980).
Hurly, J.J., and Moldover, M.R., "Ab Initio Values of the Thermophysical Properties of Helium as Standards, J. NIST Res. (2000, 105, 5).
Hurly, J.J., Schmidt, J.W., Boyes, S.J., and Moldover, M.R., "Virial Equation of State of Helium, Xenon, and Helium-Xenon Mixtures from Speed-of-Sound and Burnett PT Measurements, Int. J. Thermophys, (1997, 18, 579).

Footnote:

# is used for properties obtained from estimation methods.
* and + are used to distinguish between differing data sets within a single column.

Chemistry, Electronics, Semiconductors, Standards, Reference data and Reference materials

Contacts

Keith A Gillis

keith.gillis@nist.gov

(301) 975-2468
Michael R Moldover

michael.moldover@nist.gov

(301) 975-2459

Created December 29, 2009, Updated March 1, 2023