Vacuum technology - Vacuum gauges - Specification for hot cathode ionization gauges
1 Scope
This document defines terms relating to hot cathode ionization vacuum gauges, and specifies which parameters are given by manufacturers of hot cathode ionization gauges and which measurement uncertainties have to be considered when operating these gauges. The reasons for this are as follows.
a) This document updates some terms and definitions given in ISO 3529-3:1981.
b) This document specifies information for suitable laboratories to correctly calibrate vacuum gauges under high and ultra-high vacua, since ionization gauges with hot cathodes are often used as reference standards. This information consists of the relevant parameters and characteristics suitable for quotation in manufacturers' instructions to users employing ionization gauges for traceable measurement of pressure under high or ultra-high vacua.
c) This document also lists those uncertainties associated with the measurement of pressure by the ionization gauge, which are known to be significant, and gives guidelines on how to evaluate them. It is possible that the list is not comprehensive for some current or future vacuum gauges.
d) This document complements ISO/TS 3567 and ISO/TS 27893 when using ionization gauges as reference standards
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 27418-2017 Guide to the evaluation and expression of uncertainty in measurement (ISO/IEC Guide 98-3:2008, MOD)
Note: There is no technical difference between the contents quoted in GB/T 27418-2017 and those quoted in ISO/IEC Guide 98-3:2008.
ISO/TS 3567 Vacuum gauges - Calibration by direct comparison with a reference gauge
Note: GB/T 34873-2017 Vacuum gauges - Calibration by direct comparison with a reference gauge (ISO 3567 : 2011. IDT)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 Definitions of components
3.1.1
gauge head
gauge tube
part of the gauge that is exposed to the vacuum
[Source: ISO 3529-3:1981, modified]
Note: The gauge head of the hot cathode ionization gauge contains at least a cathode or filament, anode, ion collector and the corresponding electrical vacuum feedthroughs. See Figure A.1 in Annex A.
3.1.2
control unit
controller
part of the ionization gauge which comprises the electrical circuits necessary to energize the tube, to control and measure currents or voltages, and, in some cases, to supply power for degassing of tube elements
Note 1: See Figure B. 1 in Annex B.
Note 2: This replaces the definition for "gauge control unit" in ISO 3529-3:1981.
3.1.3
Integrated type
active gauge type
transmitter type
gauge in which the tube and controller form one piece of equipment which may be separated for baking
Note: See Figure 1 a).
3.1.4
separated type
passive gauge type
gauge in which the tube and gauge controller are separate pieces of equipment connected by a cable
Note: See Figure 1 b).
3.1.5
single gauge
one gauge in one piece of equipment
Note: See Figure 2 a).
3.1.6
combined gauge
more than one gauge in one piece of equipment
Note: See Figure 2 b).
3.1.7
envelope
wall of metal or glass that encloses the operating elements of a vacuum gauge
