Halogen quenched Gamma radiation detector with neoprene sheath for portable use.

The CV2247 Geiger–Müller tube was used in the 'British Contamination Meter No. 1'. The construction is a glass tube with a thick neoprene rubber protection boot over the tube. The connector is proprietary to the British Contamination Meter No. 1. This tube came with a complete Contamination Meter No. 1.

Specs:

• Operating temperature range: -55 to +50°C
• Threshold voltage (at 20°C): 315 to 375 V
• Operating voltage (at 20°C): 355 to 415 V
• Plateau slope (per volt): 0.07% avg, 0.15% max
• Plateau length: 150 V avg, 90 V min
• Filling: Halogen, ?
• Useful life: > 10^9 counts
• Measures 125x32mm
• Weight (without rubber boot): 39g

Geiger–Müller Counter Tube 3G88. Never issued French Army surplus, manufactured 1960s.

This is a low sensitivity Geiger–Müller tube designed for use in high radiation detecting counters.

Excerpt from 1964 technical journal showing some of the tube specs:

Geiger–Müller Counter Tube 3G88 - Under license of the French Atomic Energy Agency, a wide-range counter operating in the Geiger–Müller region has been developed for use in military equipment.
In a suitable circuit, it will respond to fields from 0.001 to 1000 roentgens per hour without saturation. It will operate on 1 stroke per second per milliroentgen per hour.
The tube, shown in Figure 9, is operable from -40 to +70 degrees centigrade. The Geiger–Müller threshold is 445 volts and a flat operating range occurs over at least 100 volts.
The minimum detectable gamma and beta energies are 50 and 2000 kiloelectron-volts, respectively. The tube is 46 millimeters ( 1.8 inches) long and 13 millimeters (0.5 inch) in diameter.

Laboratoire Central de Telecommunications France

• Weight: 5.7g
• Length: 44.8mm/1.763”
• Diameter: 12.4mm/0.490”

The DOB-50 Geiger–Müller Tube was designed in East Germany during the Cold War period, around 1970, and was produced for use in the Polish military.

This is a low sensitivity Geiger–Müller tube and this partucular one was taken from a non-working Polish DP-66M Geiger counter.

Specs:

• Operating Temperature Range -50 to +50 C
• Recommended Anode Resistor: 10m
• Operates at 390-490V
• Starting Voltage: 350v
• Recommended Operating Voltage 390V
• Peak voltage not to exceed 500v
• Plateau length is 50V
• Sensitive to Gamma and Beta
• Lifetime usage is estimated to be 950 years with continuous average background of 2 CPM

• Weight: 5g
• Length: 70mm/2.75”
• Diameter: 10mm/0.375”

Like the DOB-50, the DOB-80 Geiger–Müller Tube was designed in East Germany during the Cold War period, around 1970, and was produced for use in the Polish military.

This is a low sensitivity Geiger–Müller tube and this partucular one was taken from a non-working Polish DP-66M Geiger counter.

Specs:

• Operating Temperature Range -40 to +50 C
• Recommended Anode Resistor: 5m
• Starting Voltage: 400V
• Operating Voltage Range 490 – 590V
• Recommended Operating Voltage: 550v
• Sensitivity: Gamma, Beta and X-Rays
• Construction: Glass envelope
• Cathode Material: Stainless Steel
• Anode Material: Tungsten
• Lifetime: 2 x 10(9) (2 billion /292 years at avarage background CPM)

• Weight: 7g
• Length: 70mm/2.75”
• Diameter: 11mm/0.4375”

Metal walled, Halogen quenched high sensitivity Geiger–Müller tube. Used in Victoreen and Lionel CD V-700 Civil Defence Geiger counters during the Cold War period

This partucular tube is from a Victoreen CD V-700 6b that has been stripped down for refurbishment.

Specs:

• Operating Temperature Range -30 to +50 C
• Recommended Anode Resistor: 5m
• Starting Voltage: 860V
• Operating Voltage Range 860 – 920V
• Recommended Operating Voltage: 890v
• Sensitivity: Gamma, Beta
• Filling: Halogen, ?
• Construction: Metal wall

• Weight: 17.3g
• Length: 95mm/3.74”
• Diameter: 15.6mm/0.614”

Little is known about this tube at this time. This tube resides in a F&H FH 40 H

Some text relating to a similar tube - FHZ76V: 'this counter tube is actually a Philipps / Valvo 18550, there is also Data sheets. The counter tube is also compatible with the following tubes: Centronics ZP1320, Mullard Mx164 and LND-713. According to the Data sheet of the ZP1320 the tube is "calmed" to 9cps / mR / h at Cs-137 (Cesium, 540cpm / mR / h)'

Specs:

Stainless Steel tube inside a glass envelope. A new tube to the market and was seen around 2022. These are commonly found in cheap Chinese Geiger counters

This partucular tube is from cheap, Chinese, HFS-P3 pen type Geiger counter.

Specs:

• Operating Temperature Range -20 to +50 C
• Starting Voltage: 280 - 350V
• Minimum Floor Length: 100V
• Operating Voltage Range 400 – 500V
• Recommended Operating Voltage: 420v
• Maximum Voltage: 550v
• Sensitivity: Gamma, X-Rays
• Construction: Stainless Steel
• Working range: 0.005-20 cGy/hr
• Gamma Co60 sensitivity: 10 cps/mR/h / 68.4 cpm/μSv/hr
• Dead time: 15μs
• Background Level (10 minute average): 8cpm
• Life Expectancy: > 10^9 pulses

• Weight: 1.65g
• Length: 48mm (without leads)
• Effective Length: 30mm
• Diameter: 6.5mm
• Effective Diameter: 4mm

Tin oxide cathode, coaxial cylindrical thin glass shell structure, Halogen quenched Geiger–Müller tube from Shenzhen Sunvision Electronics Tech LTD

Pictured left - the left tube is a J305βγ from 2019. Sadly the marking have rubbed off when cleaning. The middle tube is a slightly wider, more recent J305βγ from 2023 and the tube on the right (missing it's end caps) was taken from a Cheap FS2011 Geiger counter. This may be a counterfeit GM tube as it bears no marnings and the construction differs slightly to the two with markings. At the time of writing, the J305 Geiger–Müller tube seems to be synonymous with cheap Chinese Geiger counters.

Some J305 Geiger–Müller tubes are sensitive to light and can cause erronous readings when subbject to UV or sunlight. However, some are not. The tube pictured left is light sensitive, yet the tube in the middle is not.

Specs:

• Operating Temperature Range -40 to +55 C
• Starting Voltage: 350V
• Minimum Floor Length: 80V
• Operating Voltage Range 360 – 440V
• Recommended Operating Voltage: 380v
• Maximum Voltage: 550v
• Sensitivity: Gamma, Beta
• Filling: Halogen, ?
• Construction: Tin oxide Cathode, Glass wall
• Gamma Co60 sensitivity: 44 cps/mR/h / 4.4 cps/μGy/hr
• Background Level: 25cpm
• Life Expectancy: > 10^9 pulses

• Weight: 1.65g
• Length: 107mm
• Effective Length: 87mm
• Diameter: 10.5mm
• Effective Diameter: 10mm

Mica end window Alpha, Halogen quenched, Beta and Gamma Geiger–Müller tube from LND Inc.

A very compact yet sensitive end window Alpha, Beta and Gamma detecting Geiger–Müller tube. This tube was taken from a Sparkfun Geiger counter board. An excellent tube for small, protable counters such as the Gamma Scout.

Specs:

• Operating Temperature Range -40 to +75 C
• Starting Voltage: 325V
• Operating Voltage Range 450 - 650V
• Recommended Operating Voltage: 500V
• Tube capacitance: 3pF
• Minimum dead time: 90μs
• Sensitivity: Gamma, Beta, Alpha
• Filling: Halogen, Neon
• Construction: 446 Stainless Steel Cathode, Mica window
• Gamma Co60 sensitivity: 18 cps/mR/h
• Maximum background shielded 50mm Pb + 3mm Al: 10cpm

• Weight: 6.2g (without protective cap)
• Length: 49.2mm/1.94”
• Effective Length: 38.1mm/1.5”
• Diameter: 15.1mm/0.59”
• Effective Diameter: 9.1mm/0.36”

Tin oxide cathode, coaxial cylindrical thin glass shell structure, Halogen quenched Geiger–Müller tube, quite similar to the J305.

This tube came in a GQ Electronics GMC-320 Geiger counter.

Specs:

• Operating Temperature Range -40 to +55 C
• Starting Voltage: 350V
• Operating Voltage Range 380 - 450V
• Recommended Operating Voltage: 380V
• Minimum Floor Length: 80V
• Sensitivity: Gamma, Beta
• Filling: Halogen, ?
• Construction: Tin oxide Cathode, Glass wall
• Wall density: 50±10cg/cm2
• Own Background: 25cpm

• Weight: 3.8g
• Length: 88mm
• Diameter: 10mm

Halogen quenched, end window, beta Geiger–Müller tube. Also known as the Mullard ZP1470

This tube lives in the probe of a Mini Instruments GM Meter type 5.10. They were commonly used in medical geiger counters in hospitals.

Specs:

• Operating Temperature Range -55 to +75 C
• Recommended Anode Resistor: 2.7m
• Starting Voltage: 500V
• Recommended Operating Voltage: 600V
• Minimum Floor Length: 150V
• Maximum Voltage: 700v
• Sensitivity: Beta (some Gamma and some Alpha, as tested).
• Dead time: 60μs
• Filling: Halogen, Neon, Argon
• Construction: Chrome Iron (27% Chrome) Cathode, Mica window
• Window thickness: 1.5-2.5mg/cm2
• Window Effective Diameter: 24.1mm
• Cathode thickness: 0.9mm
• Cathode Sensitive Length: 26mm
• Own Background: 25cpm

• Length: 67mm
• Diameter: 34.9mm

Halogen quenched, Gamma sensitive Geiger–Müller tube. Also known as the Mullard MX120 and Philips 18520 and is very similar to the Robotron 70 013.

This tube lives in a beautiful Panax TM64 B. Whilst the datasheet is dated 1980, the counter in which it lives is from circa 1960. The tube pictured is next to a STS-5 GM tube.

Specs:

• Operating Temperature Range -40 to +70 C
• Recommended Anode Resistor: 2.7m
• Starting Voltage: 350V
• Recommended Operating Voltage: 450V
• Minimum Floor Length: 100V
• Maximum Voltage: 500v
• Sensitivity: Gamma
• Dead time: 200μs
• Filling: Halogen, Neon, Argon
• Construction: Chrome Iron Cathode
• Cathode thickness: 525 mg/cm2
• Cathode Sensitive Length: 140mm
• Own Background: 50cpm
• Life Expectancy: > 5*10^10 pulses

• Length: 170mm
• Diameter: 23.4mm

Alpha, Beta, Gamma and Neutron radiation (with modification) sensitive, end window, Geiger–Müller tube with Halogen quenching agent. Also known as the Mullard/Centronic ZP1400.

This tube is almost identical to the LND 712, and can be used as a drop-in replacement.

Specs:

• Operating Temperature Range -55 to +75 C
• Recommended Anode Resistor: 10m
• Starting Voltage: 325V
• Recommended Operating Voltage: 500V
• Minimum Floor Length: 200V
• Maximum Voltage: 500v
• Sensitivity: Gamma, Beta, Alpha and Thermal Neutrons with modification
• Dead time: 100μs
• Filling: Halogen, Neon, Argon
• Construction: Chrome Iron Cathode (28% Chromium)
• Wall thickness: 250 mg/cm2
• Window thickness: 2-3 mg/cm2
• Window Effective Diameter: 9mm
• Own Background: 20cpm
• Life Expectancy: > 5*10^10 pulses

• Weight: 6.4g
• Length (including connecting pin): 50mm
• Effective Length: 40mm
• Diameter: 16.5mm
• Effective Diameter: 14.4mm

Gamma and hard Beta sensitive, metal walled, Geiger–Müller tube from Russia.

This tube is similar to a SBM-20, and this one lives in a NetIO GC10next Geiger counter.

Specs:

• Operating Temperature Range -40 to +60 C
• Starting Voltage: 340V
• Recommended Operating Voltage: 400V
• Minimum Floor Length: 80V
• Maximum Voltage: 550v
• Sensitivity: Gamma, hard Beta
• Dead time: 75μs
• Life Expectancy: > 5*10^10 pulses

• Length: 96mm
• Diameter: 10mm

High sensitivity Gamma and X-Ray sensitive, Halogen quenched, Geiger–Müller tube by VacuTec in Germany.

This tube is very similar to a Mullard MX120, ZP1210 and Philips 18520.

Specs:

• Operating Temperature Range -40 to +70 C
• Recommended Anode Resistor: 4.7m
• Starting Voltage: 350V
• Recommended Operating Voltage: 500V
• Plateau voltage range: 400 - 600V
• Minimum Floor Length: 200V
• Sensitivity: Gamma, X-Rays
• Dose sensitivity (Cs-137): 10 cps/µGy/hr
• Dose rate range: 0.2 - 8*10^3 µGy/hr
• Dead time: 100μs
• Filling: Halogen, Neon
• Construction: Chrome Iron
• Own Background: ≤ 1cps
• Life Expectancy: > 6*10^10 pulses

• Weight: 48g
• Length (excluding wires): 163mm
• Effective Length: 131mm
• Cathode Diameter: 20.5mm
• Anode Diameter: 2mm

A miniature, Gamma and hard Beta sensitive, Halogen quenched Geiger–Müller tube.

This tiny tube is about 7 tines less sensitive than a SBM-20, and certainly smaller. In the pictures you can see it with a British Pound coin and also next to a SBM-20. Ideal for a pocket geiger counter.

Specs:

• Operating Temperature Range -50 to +60 C
• Starting Voltage: 320V
• Recommended Operating Voltage: 400V
• Plateau voltage range: 370 - 480V
• Minimum Floor Length: 100V
• Sensitivity: Gamma, hard Beta
• Dose sensitivity (Co-60): 3.3 cps/mR/hr
• Dead time: 64μs
• Filling: Halogen, Neonn
• Construction: Stainless Steel
• Own Background: 0.13cps
• Life Expectancy: > 2*10^10 pulses

• Weight: 0.7g
• Length (including connection pin): 25.5mm
• Effective Length: 20mm
• Diameter: 6mm
• Effective Diameter: 6mm

The SBM-20 is the quintessential Soviet Geiger–Müller tube from the 1970s to the 1990s

Pictured left is an older, original style SBM-20 tube from the 1970's. Center is a more modern version from around the 1990's. Right is the slightly shorter SBM-20U variant with only one end cap and the anode exposed. All three variants have the same effective sense area.

Specs:

• Temperature range: -60°C to +70°C
• Operative Voltage: 350V min 400V typ 475V max
• Initial Voltage: 260V min 320V max
• Plateau length: 100V min
• Plateau slope: 0,1%/V max
• Dead time: 190μS min (@ 400V)
• Filling: Neon, Bromine, Argon
• Capacitance: 4,2 pF
• Life: 20 billion pulses
• Anode resistor: 4.7 MegaOhm

• Working range: 0.004-40 μR/s = 0.014-144 mR/h
• Gamma Ra226 sensitivity: 29 cps/mR/h
• Gamma Co60 sensitivity: 22 cps/mR/h
• Inherent Background: 1 cps

• Gas filling: Neon + Bromine + Argon
• Stainless steel cathode
• External length: 108mm
• Effective tube length: 90mm
• External diameter: 11mm max
• Effective tube diameter: 9.5mm
• Wall density: 40 mg/cm^2
• Wall thickness: 0.05mm
• Weight: 10 g

A small, low sensitivity, Gamma and hard Beta Geiger–Müller tube.

This tube is hardly sensitive due to the cathode size and is intended for use in high radiation environments. It shows next to no background counts.

Specs:

• Operating Temperature Range -40 to +50 C
• Starting Voltage: 330V
• Recommended Operating Voltage: 390V
• Minimum Floor Length: 80V
• Sensitivity: Gamma, hard Beta
• Construction: Glass Tube

• Weight: 3.4g
• Length: 51mm
• Effective Length: 6mm approx
• Diameter: 9.5mm
• Effective Diameter: 2.6mm approx

A large, high sensitivity, end window pancake Geiger–Müller tube, sensitive to soft Beta.

This is a thing of beauty, and a joy forever. Very sensitive to small sources. This tube is quite fragile due to it's thin Mica window. The glue fixing the tube to the Bakelite back failed, so this was an ideal opportunity to photagraph it's innards.

Specs:

• Operating Temperature Range -50 to +60 C
• Starting Voltage: 305V
• Recommended Operating Voltage: 390V
• Minimum Floor Length: 100V
• Dead time: 160μS
• Sensitivity: Soft Beta, Gamma, hard Beta
• Sensitivity to Со-60 with DER 1 μR/s: 350÷500
• Sensitivity to Сs-137 with DER 3 μR/s: 250÷310
• Efficiency to beta radiation, %: 50÷85
• Own Background: 2cps
• Life Expectancy: > 1*10^10 pulses
• Construction: Mica Window

• Weight: 93g
• Length: 30mm
• Diameter: 80mm
• Effective Diameter: 71mm approx

A miniature, low sensitivity, mica end-window, Gamma and hard Beta Geiger–Müller tube.

This tube is possibly the smallest Mica end-window Geiger–Müller tube in the world. It is not very sensitive due to it's size. The window is approximately 6mm diameter. This tube was shipped from Ukraine and came with a couple of bits of paper in Russian. In the pictures you can see the tube next to a CR2032 battery and also next to an Am-241 button.

Specs:

• Operating Temperature Range -40 to +50 C
• Sensitivity Radiation: 1000-1500 Pulses/s/R/h
• Plateau Inclination: 0.25%/V
• Working Voltage: 360-440V
• Maximum Registering Range: 900 Roentgen/hour
• Construction: Metal Wall / Mica Window

• Weight: 4g
• Length: 20mm
• Diameter: 9.3mm

A large, high sensitivity, Gamma and hard Beta Geiger–Müller tube made for the Soviet Military.

This tube is quite sensitive due to it's size. Ideal for use in monitoring equipment and dosimeters.

Specs:

• Operating Temperature Range -50 to +70 C
• Starting Voltage: 335V
• Recommended Operating Voltage: 390V
• Minimum Floor Length: 100V
• Sensitivity: Gamma, hard Beta
• Sensitivity to Со-60: 540 pulse/mkR
• Own Background: 1.16cps
• Construction: Metal Wall

• Weight: 35.6g
• Length: 215mm
• Effective Length: 160mm approx
• Diameter: 18.5mm

Moderately sensitive. Detects Gamma and hard Beta. This tube is very similar to the SBM-20.

Whilst the electrical specs are very similar to the SBM-20, it should be noted that the STS-5 tube is slightly longer than the SBM-20. It can serve as a drop-in replacement for the SBM-20, but it might not quite fit due to it's length.

Specs:

• Operating Temperature Range -40 to +50 C
• Recommended Anode Resistor: 5 - 10m
• Starting Voltage: 330V
• Recommended Operating Voltage: 400V
• Minimum Floor Length: 80V
• Sensitivity: Gamma, hard Beta
• Own Background: 0.45cps
• Construction: Metal Wall

• Weight: 8g
• Length: 110mm
• Diameter: 12mm

Energy compensated, Halogen quenched, Gamma sensitive Geiger–Müller tube with compensating filter and long life artificial background.

The datasheet linked here is for the ZP1301, but states 'also availaable with long life artificial background as ZP1302. This tube lives in a Plessey PDRM 82, as shown in one of the pictures. It was removed for photographing.'

Specs:

• Operating Temperature Range -40 to +70 C
• Recommended Anode Resistor: 2.2m
• Starting Voltage: 400V
• Recommended Operating Voltage: 550V
• Minimum Floor Length: 100V
• Maximum Voltage: 600v
• Dead time: 13μS
• Filling: Halogen, Helium, Neon
• Sensitivity: Gamma
• Dose rate range: 10^-1 to 2*10^4 mGy/h
• Own Background: 12-120cpm
• Life Expectancy: > 1*10^10 pulses
• Construction: Chrome Iron Cathode 80-100 mg/cm2

• Length (including connection pin): 28.5mm
• Effective Length: 8mm
• Diameter: 13.7mm