Specialized - Radiation Counter ·GeigerMullerCounter
Miniature mica-window Geiger-Müller counter designed primarily for beta measurements in laboratory and field instruments. A long self-quenching plateau and windowed construction provide practical sensitivity for portable radiation work.
The 1B102, also designated as the 1B102 Thyrode, is a halogen-quenched, mica-window beta counter tube designed to meet both laboratory and field requirements for beta radiation detection. It features a ruggedized design with significantly greater resistance to vibration and shock compared to the 1B67.
The 1B102 is constructed with a thin mica window and utilizes a halogen quenching gas. The halogen quench practically eliminates photosensitivity and mitigates the effects of static charges on the window, ensuring stable operation under varying environmental conditions.
The tube is housed in a cylindrical envelope and is fitted with an RMA medium 4-pin tube base. The base pins have asymmetrical diameters to ensure correct orientation: two pins have a diameter of 0.125 inches, and the other two pins have a diameter of 0.156 inches.
The 1B102 utilizes a standard RMA medium 4-pin base configuration. When viewed from the bottom (base view), the electrical connections are assigned as follows:
| Pin Number | Connection |
|---|---|
| Pin 1 | Unlabeled / No Connection |
| Pin 2 | Anode (A) |
| Pin 3 | Unlabeled / No Connection |
| Pin 4 | Cathode (K) |
The electrical parameters of new 1B102 tubes are characterized by a well-defined plateau and low background count rate.
| Parameter | Specification |
|---|---|
| Threshold Voltage | Max. 825 V |
| Plateau Length | Min. 150 V |
| Plateau Slope | Max. 10% / 100 V (measured from V_0 = 800 to 1000 V) |
| Recovery Time | 200 µsec |
| Background Count Rate | 40 C/M (at V_0 = 900 V) |
| Electrode Capacitance | 2.5 µµF |
| Operating Life | Unlimited by use (tested at 6000 C/M, V_0 = 900 V) |
The 1B102 is rated for reliable operation under a wide range of environmental conditions, making it suitable for portable field instruments as well as laboratory setups.
The performance of the 1B102 is characterized by its counting rate and charge per pulse behavior across its operating voltage range:
The 1B102 is a specialized, halogen-quenched beta counter tube featuring a 2 mg/cm² mica window and an active length of 1.7 inches. Housed in a 1.240-inch diameter envelope with an RMA medium 4-pin base, it offers robust resistance to shock and vibration, making it a highly durable alternative to the 1B67. Operating within a voltage range of 850 V to 950 V, the tube provides a minimum plateau length of 150 V with a maximum slope of 10% per 100 V. Its halogen fill ensures stable, photosensitivity-free performance across extreme temperatures (-55 °C to +70 °C) and up to 100% relative humidity, delivering virtually unlimited service life for both laboratory and field beta-counting applications.
Medium 7-contact transmitting-tube base
General specifications
Properties common to every published source and operating point.
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
1 physical section, each with unique specifications.
Section 0
No fixed ratings are recorded for this section.
Source-dependent data
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 01
Published operating points and test conditions from this source.
ThresholdVoltage
825 V
Max
Operating Voltage
850 to 950 V
PlateauLength
150 V
Minimum
PlateauSlope
10 %/100V
Maximum
RecoveryTime
200 us
Background
40 counts/min
BetaEfficiency
99 %
WindowMass
1.7 mg/cm2
ElectrodeCapacitance
2.5 pF