Latest revision as of 14:59, 1 December 2023

The Siemens Logo as seen in 1971

The Siemens Corperation has, throughout the years produced many things, among them was the very First Electron Microsocpe. The history of the Electron Microscope started with Siemenes and Ernst Ruska, together with his research team, they created the very first Electron Microscopes.

Timeline

1961-01-01/1971-01-01|EPMA|Elmisonde

1977-01-01/1978-01-01|STEM|Elmiskop ST100F

Models

Siemens, as the company responsible for the invention of the Electron Microscope has produced many models throughout the years, also selling a rebadged version of the Etec Autoscan which was sold under the Siemens name outside the United States. Most of their models however where of the Transmission kind, mostly due to Ernst Ruskas Prescience.

Transmission Electron Microscops

General
Year	1938
Successor	Prototyp 2

Electron Source
Accelerator Type	Kanalstrahlrohr
Acellerating Voltage	75 KV
Cathode	Gas Discharge

Condenser
Lens Type	Electromagnetic

Stage
Holder Type	Cartridge, Top Entery

Objective
Lens Type	Electromagnetic

Projective Lens
Lens Type	Electromagnetic
No. of Lenses	1

General
Year	1938
Successor	Übermikroskop

Electron Source
Accelerator Type	Kanalstrahlrohr
Acellerating Voltage	75 KV
Cathode	Gas Discharge

Condenser
Lens Type	Electromagnetic

Stage
Holder Type	Cartridge, Top Entery

Objective
Lens Type	Electromagnetic
Resolution	100a

Projective Lens
Lens Type	Electromagnetic
No. of Lenses	1

General
Year	1939
Successor	ÜM100

Electron Source
Accelerator Type	Kanalstrahlrohr
Acellerating Voltage	75 KV
Cathode	Gas Discharge

Condenser
Lens Type	Electromagnetic

Stage
Holder Type	Cartridge, Top Entery

Objective
Lens Type	Electromagnetic
Resolution	100a

Projective Lens
Lens Type	Electromagnetic
No. of Lenses	1

General
Year	1949
Successor	Elmiskop I
Chamber Pressure	1·10⁻⁴ Torr

Electron Source
Accelerator Type	Self Biased Triode
Acellerating Voltage	40 KV, 60 KV, 80 KV, 100 KV
Cathode	Tungsten Hairpin

Condenser
Lens Type	Electromagnetic

Stage
Holder Type	Cartridge, Top Entery

Objective
Lens Type	Electromagnetic

Projective Lens
Lens Type	Electromagnetic
No. of Lenses	1

General
Year	1950
Successor	Elmiskop II

Electron Source
Accelerator Type	Self Biased Triode
Acellerating Voltage	40, 50, 60 KV
Cathode	Tungsten Hairpin

Condenser
Lens Type	Electromagnetic

Stage
Holder Type	Cartridge, Top Entery

Objective
Lens Type	Electromagnetic

Projective Lens
Lens Type	Electromagnetic
No. of Lenses	1

General
Year	1954
Successor	Elmiskop IA
Mag. Range	200x - 200Kx
Mag. Gauge	Galvanometer
Chamber Pressure	1·10⁻⁴ Torr
Power Requirment	3.3 KVA
System Weight	1200 Kg

Electron Source
Accelerator Type	Self Biased Triode
Acellerating Voltage	40, 60, 80, 100 KV
Stability	2·10⁻⁵⁄ₘᵢₙ
Cathode	Tungsten Hairpin
Cathode Heating	AC

Condenser
Lens Type	Electromagnetic
Nu. of Lenses	2
Stability	1·10⁻³⁄ₘᵢₙ
Stigmator	Moveing Iron
Spot Size	2µm

Stage
Holder Type	Cartridge, Top Entery

Objective
Lens Type	Electromagnetic
Focal Length	2.8mm
Stability	1·10⁻⁵⁄ₘᵢₙ
Range	2.8mm to 7.4mm
Spherical Error	3.3 mm
Resolution	5Å

Projective Lens
Lens Type	Electromagnetic
No. of Lenses	2
Stability	1·10⁻⁴⁄ₘᵢₙ
Configuration	4 Polpiece Revolver
Pol Piece Mag.	12.5:1, 31.2:1, 62.5:1, 125:1, 250:1

General
Year	1954
Successor	Elmiskop II

Electron Source
Accelerator Type	Self Biased Steigerwald Triode
Acellerating Voltage	40, 50, 60 KV
Cathode	Tungsten Hairpin

Stage
Holder Type	Cartridge, Top Entery

Objective
Lens Type	Electromagnetic
Stability	3·10⁻⁵⁄ₘᵢₙ
Resolution	25Å

Projective Lens
Lens Type	Electromagnetic
No. of Lenses	1
Configuration	4 Polpiece Revolver

General
Year	1955
Successor	Elmiskop 51
Mag. Range	295x, 1925x, 8Kx, 17Kx, 35Kx
Chamber Pressure	1·10⁻⁴Torr
Power Requirment	2 KVA
System Weight	700 Kg

Electron Source
Accelerator Type	Self Biased Steigerwald Triode
Acellerating Voltage	50 KV
Stability	5·10⁻⁵⁄ₘᵢₙ
Cathode	Tungsten Hairpin

Condenser
Stigmator	Moveing Iron

Stage
Holder Type	Cartridge, Top Entery

Objective
Lens Type	Electromagnetic
Focal Length	1.8mm
Stability	3·10⁻⁵⁄ₘᵢₙ
Range	2.8mm to 7.4mm
Resolution	15Å

Projective Lens
Lens Type	Electromagnetic
No. of Lenses	1
Configuration	4 Polpiece Revolver
Pol Piece Mag.	16.9:1, 69.9:1, 146:1, 300:1

General
Year	1956

Electron Source
Accelerator Type	Self Biased Steigerwald Triode
Acellerating Voltage	50 KV
Stability	5·10⁻⁵⁄ₘᵢₙ
Cathode	Tungsten Hairpin

Condenser
Stigmator	Moveing Iron

Objective
Lens Type	Permanent Magnet
Resolution	25-50Å

Projective Lens
Lens Type	Permanent Magnet
No. of Lenses	1
Configuration	4 Polpiece Revolver

General
Year	1961
Successor	Elmiskop 101
Mag. Range	200x - 200Kx
Mag. Gauge	Galvanometer
Chamber Pressure	1·10⁻⁴Torr
Power Requirment	3.3 KVA
System Weight	1200 Kg

Electron Source
Accelerator Type	Self Biased Triode
Acellerating Voltage	40, 60, 80, 100 KV
Stability	2·10⁻⁵⁄ₘᵢₙ
Cathode	Tungsten Hairpin
Cathode Heating	AC

Condenser
Lens Type	Electromagnetic
Nu. of Lenses	2
Stability	1·10⁻³⁄ₘᵢₙ
Stigmator	Moveing Iron
Spot Size	2µm

Stage
Holder Type	Cartridge, Top Entery

Objective
Lens Type	Electromagnetic
Focal Length	2.8mm
Stability	1·10⁻⁵⁄ₘᵢₙ
Range	2.8mm to 7.4mm
Spherical Error	3.3 mm
Resolution	5Å

Projective Lens
Lens Type	Electromagnetic
No. of Lenses	2
Stability	1·10⁻⁴⁄ₘᵢₙ
Configuration	4 Polpiece Revolver
Pol Piece Mag.	12.5:1, 31.2:1, 62.5:1, 125:1, 250:1

General
Year	1968
Successor	Elmiskop 102
Mag. Range	285x - 260Kx
Mag. Gauge	Galvanometer

Electron Source
Accelerator Type	Self Biased Triode
Acellerating Voltage	40, 60, 80, 100, 125 KV
Cathode	Tungsten Hairpin

Condenser
Lens Type	Electromagnetic
Nu. of Lenses	2
Stigmator	Electromagnetic Octopol

Stage
Holder Type	Cartridge, Top Entery

Objective
Lens Type	Electromagnetic

Projective Lens
Lens Type	Electromagnetic
No. of Lenses	2
Configuration	2 Polpiece Revolver

General
Year	1972
Successor	Elmiskop 103
Mag. Range	200x - 500Kx
Mag. Gauge	Digital
Chamber Pressure	5·10⁻⁶ Torr
Power Requirment	4 KVA
System Weight	Kg

Electron Source
Accelerator Type	Self Biased Triode
Acellerating Voltage	20, 40, 60, 80, 100, 125 KV
Stability	2·10⁻⁶⁄ₘᵢₙ
Cathode	Tungsten Hairpin, Tungsten Lancet
Cathode Heating	DC

Condenser
Lens Type	Electromagnetic
Nu. of Lenses	2
Stability	5·10⁻⁶⁄ₘᵢₙ
Stigmator	Electromagnetic Octopol
Spot Size	1.7µm / 0.5 µm

Stage
Holder Type	Cartridge, Top Entery

Objective
Lens Type	Electromagnetic
Focal Length	2.7mm
Stability	< 2·10⁻⁶⁄ₘᵢₙ
Range	1.6mm (20KV) to 7mm
Spherical Error	2.9 mm
Chromatic Error	2.1 mm
Resolution	3Å

Projective Lens
Lens Type	Electromagnetic
No. of Lenses	3
Stability	<5·10⁻⁶⁄ₘᵢₙ
Configuration	Single Polpiece

General
Year	1977
Mag. Range	500x - 1200Kx
Mag. Gauge	Digital
Chamber Pressure	5·10⁻⁶ Torr
Power Requirment	5.5kVA
System Weight	1800Kg

Electron Source
Accelerator Type	Self Biased Triode
Acellerating Voltage	20, 40, 60, 80, 100, 125, 150 KV
Stability	2·10⁻⁶⁄ₘᵢₙ
Emmision Current	100nA → 100µA
Cathode	Tungsten Hairpin, Tungsten Lancet
Cathode Heating	DC

Condenser
Lens Type	Electromagnetic
Nu. of Lenses	2
Stability	<5·10⁻⁶⁄ₘᵢₙ
Stigmator	Electromagnetic Octopol
Spot Size	500 nm / 200 nm

Stage
Holder Type	Side Entry

Objective
Lens Type	Electromagnetic
Focal Length	1.7mm
Stability	< 2·10⁻⁷⁄ₘᵢₙ
Spherical Error	1.4 mm
Chromatic Error	1.3 mm
Resolution	3Å

Projective Lens
Lens Type	Electromagnetic
No. of Lenses	3
Stability	<5·10⁻⁶⁄ₘᵢₙ
Configuration	Single Polpiece

General
Year	1977
Mag. Gauge	Digital

Electron Source
Accelerator Type	Self Biased Triode
Acellerating Voltage	20, 40, 60, 80, 100 KV ?

~

Scanning Transmission Electron Microscops

Elmiskop ST100F

General
Year	1977
Successor	none
Magnification Range	50x - 10e7X
Magnification Gauge Type
Specemin Chamber Pressure	10e-7 mBar
Power Consumption
System Weight

Electrion Source
Accelerator Type	Crewe FE Electron Gun
Cathode Type	Cold Field Emmision
Accelerating Voltage	20, 40, 60, 80, 100 KV, (10 - 30 KV)
Stability	2*10e-6
Cathode Heating Methode	N/A
Alignment Methode

Condensor
Number of Condensor Lenses	1
Current Stability	2*10e-6
Stigmator
Minimum Spot Size Diameter
Condensor Alignment
Lens Type	Crewe Electrostatic

Stage
Holder Type
X, Y Travel Range	+- 1 mm

Objective Lens
Focal Length	1.8 mm
Adjustment Range
Spherical Error	1.3 mm
Chromatic Error	1.3 mm
Current Stability	1 * 10e-6
Stigmator	Electromagnetic
Alignment Aids
Point Resolution	2 Å
Lens Type	Electromagnetic

Projective Lens
Number of Projective Lens
Current Stability
Polpeace Configuration
Avalible Polpeace Magnifications
Alignment
Lens Type

X-Ray Micro Analyzers

Elmisonde

General
Year	1961
Successor	none
Magnification Range
Magnification Gauge Type
Specemin Chamber Pressure
Power Consumption
System Weight

Electrion Source
Accelerator Type	Single Stage Electron Gun
Cathode Type	Tungsten Hairpin
Accelerating Voltage	40, 60, 80, 100 KV
Stability	2*10⁻⁵/min
Cathode Heating Methode	AC
Alignment Methode	X, Y, Mechanical

Condensor
Number of Condensor Lenses	2
Current Stability
Stigmator	Moveing Iron, Mechanical
Minimum Spot Size Diameter
Condensor Alignment	X, Y, and Tilt, Mechanical
Lens Type	Electromagnetic

Stage
Holder Type	Cartridge, Top Entry
X, Y Travel Range	± 0.8 mm

Objective Lens
Focal Length
Adjustment Range
Spherical Error
Current Stability
Stigmator	Moveing Iron, Mechanical
Alignment Aids
Point Resolution
Lens Type	Electromagnetic

Projective Lens
Number of Projective Lens	1
Current Stability
Polpeace Configuration	4 Position Revolver
Avalible Polpeace Magnifications
Alignment
Lens Type	Electromagnetic

Scanning Electron Microscops

Autoscan

General
Year	1972
Successor	none
Magnification Range	20 - 550Kx
Magnification Gauge Type	Analog, (Digital)
Specemin Chamber Pressure	2 * 10-4 Torr
Power Consumption	3 KVA
System Weight

Electrion Source
Accelerator Type	Single Stage Electron Gun
Cathode Type	Tungsten Hairpin / LaB6 / Field Emission?
Accelerating Voltage	2.5, 5, 10, 20, 30, (50) KV
Stability
Cathode Heating Methode	HF
Alignment Methode	X, Y Mechanical

Condensor
Number of Condensor Lenses	3
Current Stability
Stigmator	none
Minimum Spot Size Diameter
Condensor Alignment	none, prealigned
Lens Type	3 gap Common Coil Electromagnetic

Stage
Holder Type
X, Y Travel Range	+- 12.5 mm
Z Travel Range	25 mm

Objective Lens
Focal Length
Adjustment Range
Spherical Error
Current Stability
Stigmator	Dual Quadropol Electromagnetic
Alignment Aids
Point Resolution	7 nm
Lens Type	Electromagnetic

Documentation

Full list of all documents related to the Siemens Electron Microscopes.

Categorie Entries

@@ Line 357: / Line 357: @@
 proj_stab=<5·10⁻⁶⁄ₘᵢₙ;
 proj_conf=Single Polpiece;
+|
+}}
+{{#DeviceInfoBox2:tem|Elmiskop CT100||
+OEM=File:Siemens & Halske - Logo - 1971.png;
+year=1977;
+mag_gauge=Digital;
+accel=Self Biased Triode;
+accel_volt=20, 40, 60, 80, 100 KV ?;
 |
 }}
 </br>
 <div>~</div>
+[[Category:Pages using DynamicPageList parser function]]
 == Scanning Transmission Electron Microscops ==
@@ Line 768: / Line 779: @@
 {{#tree:
 *[[Elmiskop I]]
-**Manual
+**Service
-***{"icon":false}{{#l:Siemens - Elmiskop IA - Bedienungsanleitung - Band 2 - Bilder und Pläne.pdf|Eg1/1000.16/10.64 - Bedienungsanleitung - Band 2 - Bilder und Pläne}}
+***{"icon":false}{{#l:Siemens - C70389-A2101-S116 - EO-ÜM2101-Bp7 - Stativ Bauschaltplan.pdf|C70389-A2101-S116 - EO-ÜM2101-Bp7 - Stativ Bauschaltplan}}
+***{"icon":false}{{#l:Siemens - C70389-A11-5734 - Eo ÜM11 Zb34 - Umbau des Elmiskop I-Geräts ab F Fr 288 (7 Ordner) in Geräte mit normaler und langer Brennweite.pdf|C70389-A11-5734 - Eo ÜM11 Zb34 - Umbau des Elmiskop I-Geräts ab F Fr 288 (7 Ordner) in Geräte mit normaler und langer Brennweite}}
+***{"icon":false}{{#l:Siemens - C70389-A11-S7 8 - Eo ÜM11 SK7 - Schaltteilliste zum Elmiskop I.pdf|C70389-A11-S7 8 - Eo ÜM11 SK7 - Schaltteilliste zum Elmiskop I}}
+***{"icon":false}{{#l:Siemens - C70144-A154-S6 10 - EO div 154 Sk6 - Netzanschlusschrank für Elmiskop I Sammelkarte.pdf|C70144-A154-S6 10 - EO div 154 Sk6 - Netzanschlusschrank für Elmiskop I Sammelkarte}}
+***{"icon":false}{{#l:Siemens - C70392-B8001-S2 - Eo verst 1 SK 2 - Linsenstrom-Regler Sammelkarte.pdf|C70392-B8001-S2 - Eo verst 1 SK 2 - Linsenstrom-Regler Sammelkarte}}
+***{"icon":false}{{#l:Siemens - C70280-A1-S3 - Eo na1 SK3 - Linsenstrom-Netzgerät Sammelkarte.pdf|C70280-A1-S3 - Eo na1 SK3 - Linsenstrom-Netzgerät Sammelkarte}}
+***{"icon":false}{{#l:Siemens - C70392-B8002-S1 - EO verst 2 Sk1 - Hochspannungsregler Sammelkarte.pdf|C70392-B8002-S1 - EO verst 2 Sk1 - Hochspannungsregler Sammelkarte}}
+***{"icon":false}{{#l:Siemens - C70144-A148-S4 - EO div 148 SK4 - 100 kV-Gleichrichter Sammelkarte.pdf|C70144-A148-S4 - EO div 148 SK4 - 100 kV-Gleichrichter Sammelkarte}}
+***{"icon":false}{{#l:Siemens - C71122-A3-A1.pdf| C71122-A3-A1 - Batteriekasten}}
+***{"icon":false}{{#l:Siemens - Eo verst 2 SK 1.pdf|C70392-B8002-S1 - Eo verst 2 SK 1 - Hochspannungsregler Sammelkarte}}
+***{"icon":false}{{#l:Siemens - C71280-A3-A1-A2.pdf|C71280-A3-A1-A2 - Netzanschlußschrank Elmiskop I}}
+***{"icon":false}{{#l:Siemens - C71280-A3-B2 B3.pdf|C71280-A3-B2 B3 - Luftschützplatte}}
+***{"icon":false}{{#l:Siemens - C71280-A3-B1.pdf|C71280-A3-B1 - Kondensator- und Widerstandsplatte}}
+***{"icon":false}{{#l:Siemens - C71302-A3-A1 A2.pdf|C71302-A3-A1 A2 - Linsenstrom-Regler}}
+***{"icon":false}{{#l:Siemens - C71302-A3-B2.pdf|C71302-A3-B2 - Chassis I}}
+***{"icon":false}{{#l:Siemens - C71302-A3-B9.pdf|C71302-A3-B9 - Winkel mit Relaisfassung}}
+***{"icon":false}{{#l:Siemens - C71302-A3-B10.pdf|C71302-A3-B10 - Chassis II}}
+***{"icon":false}{{#l:Siemens - C71302-A3-B16.pdf|C71302-A3-B16 - Frontplatte, kpl.}}
+***{"icon":false}{{#l:Siemens - C71302-A3-B19.pdf|C71302-A3-B19 - Schalteraufbau I}}
+***{"icon":false}{{#l:Siemens - C71302-A3-B24.pdf|C71302-A3-B24 - Schalteraufbau II}}
+***{"icon":false}{{#l:Siemens - eg uM 11 k12.pdf|C70389-A11-S12 - Schaltteilliste zum Elmiskop I}}
+***{"icon":false}{{#l:Siemens - eg uM 2702 Sk6.pdf|C70389-A2702-S6 - Eo. ÜM 2702 SK6 - Schaltteilliste zum Bedienungskasten für Elmiskop I}}
+***{"icon":false}{{#l:Siemens - EO div148 SK4.pdf|C70144-A148-S4 - EO. Div, 148 SK4 - 100 kV-Gleichrichter Sammelkarte}}
+***{"icon":false}{{#l:Siemens - Eo no 1 SK 3.pdf|C70280-A1-S3 - Eo. na 1, Sk3 - Linsenstrom--Netzgerät Sammelkarte}}
 **Promotional
-***{"icon":false}{{#l:Siemens Elmiskop 1 - Brochure.pdf|Marketing Brochure}}
+***{"icon":false}{{#l:Siemens - 1-7601-203 - Elmikop I - Brochure.pdf|1/7601-203 - Elmikop I - Brochure}}
 ***{"icon":false}{{#l:Siemens Elmiskop 1 - Grossraum Objektkammer.pdf|Grossraum Objektkammer Brochure}}
 ***{"icon":false}{{#l:Siemens Elmiskop 1 - Objektheizeinrichtung.pdf|Objektheizeinrichtung Brochure}}
@@ Line 794: / Line 832: @@
 ***{"icon":false}{{#l:Siemens - Dünnwandige Objektivaperturblenden für die Elektronenmikroskopie - comp.pdf|Dünnwandige Objektivaperturblenden Brochure}}
 ***{"icon":false}{{#l:Siemens - Einrichtung für Röntgenmikroanalyse (RMA) zum Elmiskop Ia und Elmiskop I - comp.pdf|Einrichtung für Röntgenmikroanalyse (RMA) Brochure}}
+*[[Elmiskop II]]
+**Service
+***{"icon":false}{{#l:Siemens - C70389-A13-S301 - Eo ÜM 13 str 1 - Elmiskop II Stromlaufplan.pdf|C70389-A13-S301 - Eo ÜM 13 str 1 - Elmiskop II Stromlaufplan}}
 *[[Elmiskop IA]]
 **Manual
-***{"icon":false}{{#l: Siemens-Elmiskop-IA-Band1-Bedienungsanleitung.pdf|(DE) Eg1/1000.16/10.64 - Band 1 - Bedienungsanleitung}}
+***{"icon":false}{{#l: Siemens-Elmiskop-IA-Band1-Bedienungsanleitung.pdf|Eg1/1000.16/10.64 - Band 1 - Bedienungsanleitung}}
-***{"icon":false}{{#l:Siemens - Elmiskop 1A - Band 2 - Abbildungen - EN DE.pdf|(DE / EN) Eg1/1000.16/10.64e - Band 2 - Bilder und Pläne}}
+***{"icon":false}{{#l:Siemens - Elmiskop IA - Bedienungsanleitung - Band 2 - Bilder und Pläne.pdf|Eg1/1000.16/10.64 - Band 2 - Bilder und Pläne}}
-***{"icon":false}{{#l:Siemens - Elmiskop 1A - Volume 1 - Instruction Manual.pdf|(EN)Volume 1 - Instruction Manual}}
+***{"icon":false}{{#l:Siemens - Elmiskop 1A - Band 2 - Abbildungen - EN DE.pdf|Eg1/1000.16/10.64e - Band 2 - Bilder und Pläne}}
+***{"icon":false}{{#l:Siemens - Elmiskop 1A - Volume 1 - Instruction Manual.pdf|Volume 1 - Instruction Manual}}
 *[[Elmiskop 101]]
@@ Line 809: / Line 851: @@
 ***{"icon":false}{{#l:Siemens - MWB C73000-B3100-C3-1 - Elmiskop 102 Bedienungsanleitung.pdf|MWB C73000-B3100-C3-1 - Elmiskop 102 Bedienungsanleitung}}
 ***{"icon":false}{{#l:Siemens - MWB EM Q 801def 6 76 - Transportanleitung Elmiskop 101 & 102.pdf|MWB EM Q/801def/6.76 - Transportanleitung Elmiskop 101 & 102}}
+*[[Elmiskop ST100F]]
+**Service
+***{"icon":false}{{#l:Siemens - C73389-A31-A1 A3- -98 - S1- Blatt 3- ST100F - Objektiv Sonderbauunterlage.tif|C73389-A31-A1 A3-*-98 - S1- Blatt 3- ST100F - Objektiv Sonderbauunterlage}}
+**Promotional
+***{"icon":false}{{#l:Siemens - E631-1014 - Elmiskop ST100F Brochure - German.pdf|E631/1014 - Elmiskop ST100F - Brochure}}
 *[[Elmiskop CT150]]
 **Promotional
-***{"icon":false}{{#l:Siemens - E631-1016 - Elmiskop CT150 - Brochure.pdf|E631-1016 - Elmiskop CT150 - Brochure}}
+***{"icon":false}{{#l:Siemens - E631-1016 - Elmiskop CT150 - Brochure.pdf|E631/1016 - Elmiskop CT150 - Brochure}}
+*[[ETEC / Siemens Autoscan]]
+**Promotional
+***{"icon":false}{{#l:ETEC - Seimens - E6331-1002 - Autoscan Brochure - German.pdf|E6331/1002 - Autoscan - Brochure}}
+***{"icon":false}{{#l:ETEC - Siemens - E633-1001-101 - Autoscan Brochure.pdf|E633/1001-101 - Autoscan - Brochure}}
 *Price Lists / Catalogs

Difference between revisions of "Siemens"