The 6150AD is a PTB approved dose rate meter in a waterproof housing made of aluminium die casting. The built-in GM counting tube serves to measure photon radiation (gamma and X-radiation). As implied by the letters »AD« in its name, the 6150AD provides both analog and digital display with automatic range selection. A piezo buzzer using the housing as a diaphragm, thus integrated invisibly, emits warning tones and the single pulse click. One pin of the probe connector is a serial interface that allows to read and process dose rate by a PC. The 9 Volt battery (IEC 6LR61, included) lasts for approximately 3000 operating hours.
The probe socket on the left-hand side of the instrument serves to connect external probes. Connecting a probe automatically turns off the internal counting tube and puts the probe’s detector in operation. The 6150AD automatically identifies the probe type and displays it in the upper left corner of the LCD (e.g., »ext 18« if a probe 6150AD-18 is connected). It automatically selects ranges and units for that probe type. Due to the purely digital processing you do not have to assign a certain probe to a certain 6150AD. The probe cable may be up to 100 m long.
Basically, there are two detectors with different ranges, and the instrument may have »additional functions« or not. This makes a total of four basic models as indicated in the table below (the former 6150AD3 and AD4 models are no longer required because they where replaced with AD5 and AD6). All of the four basic models are available for either the classical quantity Hx or the more modern H*(10). The latter are given the extension »/H« to their type name.
|Additional functions||Ranges for dose rate and photon energy|
|no||High range models:|
analog: 1 µSv/h – 1000 mSv/h
digital: 0.1 µSv/h – 999 mSv/h
»useful«: 0.2 mSv/h – 999 mSv/h
45 keV – 3 (/H:2.6) MeV
|no||Low range models:|
analog: 0.1 µSv/h – 10 mSv/h
digital: 0.01 µSv/h – 9.99 mSv/h
»useful«: 2 µSv/h – 9.99 mSv/h
60 keV – 1.3 MeV
The »useful« dose rate range is the range complying with German requirements for permissible fluctuations of dose rate indication. Note that all models provide the average dose rate function which allows to read very low dose rates more accurately.
The smart Hx models 6150AD5 and 6150AD6 allow the user to select either R or Sv as the unit. The simple Hx models 6150AD1 and 6150AD2 have the unit fixed to either Sv or R (please specify when ordering).
All H*(10) models (extension »/H«) are necessarily fixed to Sv units.
We have also »/E« models which are identical to »/H« models except that they do not accept old Hx probes. We had to create the »/E« models particularly for the German market, because German regulations require basic meter and probes to use the same quantity. For international use we strongly recommend »/H« models over »/E« models because this will not result in compatibility problems. Therefore we shall not further consider the »/E« models.
How to select your model? First consider the dose rates you will have to measure. If dose rates above 10 mSv/h are unlikely to occur, the AD2 or AD6 is preferred because its higher sensitivity makes it better suited at low levels. Otherwise the AD1 or AD5 is the better choice (or, for covering a very wide range, you may consider the low range model AD2 or AD6 together with the high range probe 6150AD-18(/H) ).
Secondly, should you need to measure H*(10) according to your national regulations, choose the »/H« model.
Thirdly, depending on the application, decide whether you prefer the simple models AD1 and AD2 or the smart models AD5 and AD6 providing the »additional functions« (at no extra cost). The only argument against the additional functions is that they will necessarily make operation slightly more complicated. The additional functions are:
- Protection against unintentional switching off (requires two consecutive key pushes in the ground state),
- Non-volatile memory for the internal tube’s dose,
- Dose warning,
- Programmable alarm thresholds for dose and dose rate,
- Better resolution (more places after the decimal point) when indicating dose, alarm threshold, and so on,
- Indication of the relative standard deviation of the dose rate average value,
- Recognising the Scintillator Probe 6150AD-b (/H, /E).
Gamma Probe 6150AD-15(/H)
Hx model: 6150AD-15
High Range Gamma Probe, power supply from 6150AD.
Gamma Probe 6150AD-18(/H)
Hx model: 6150AD-18
Low Range Gamma Probe, power supply from 6150AD.
Accessories for 6150AD-15(/H) and AD-18(/H)
|Probe Cable (required accessory): A Probe Cable (not included in the delivery) is definitely required for operation.|
|The Source Holder 761.2 (optional accessory) serves to mount the Check Source 6706 or equivalent onto either probe type in a well-defined position. This allows reproducible radiological checks.|
|The category Cases and Bags for 6150AD presents a number of possibilities to store and transport the probes.|
Scintillator Probe 6150AD-b
|The Scintillator Probe 6150AD-b is a portable PTB approved probe for the Dose Rate Meter 6150AD to measure photon radiation (gamma and X-radiation). A cylindrical three by three inches organic scintillator serves as the radiation detector. Particular advantages of the Scintillator Probe are its wide energy range and its high sensitivity. The Scintillator Probe is thus particularly well suited for fast and accurate measurements of low radiation levels down to or even below natural background. Due to that feature the probe received its name: the »b« in 6150AD-b means »background«. Other applications are, for example, measurement of scattered radiation and measurements around CRTs (cathode ray tubes) or other sources of X-rays.The probe is available for either the classical quantity Hx or the more modern H*(10). The latter version is given the extension »/H« to its type name.The Scintillator Probe 6150AD-b(/H) requires the smart models 6150AD5(/H) or 6150AD6(/H) as basic meters. Power supply comes from the 6150AD basic meter through the probe cable.We also have the 6150AD-b/E model which is identical to the 6150AD-b/H model except that it only works with 6150AD5/E and 6150AD6/E basic meters. Since we strongly recommend »/H« models over »/E« models for international use, we shall not further consider the 6150AD-b/E model.A helical probe cable (part number 700.1.18) and the removable carrying strap (part number 187.5) are included in the delivery, however not the 6150AD meter.Hx model: 6150AD-b|
H*(10) model: 6150AD-b/HAnalog range: 10 nSv/h – 100 µSv/h
Digital range: 1 nSv/h – 99.99 µSv/h
Approved range: 100 nSv/h – 100 µSv/h
Energy range 6150AD-b: 23 keV – 7 MeV
Energy range 6150AD-b/H: 20 keV – 7 MeV
The »approved« dose rate range starts at 100 nSv/h because according to German regulations lower dose rates are not subject to official calibration.
Contamination Probes 6150AD-17 and 6150AD-k
|The probes serve to detect contamination in conjunction with any 6150AD model. If connected to the 6150AD, the 6150AD automatically selects the unit »pulses per second«. All functions as described in the 6150AD’s data sheet remain available, where pulse rate and pulse number take the place of dose rate and dose, respectively. Both probes are supplied from the 6150AD.The indication in pulses per second needs to be multiplied by a calibration factor to convert it into surface related activity (Bq/cm²). The calibration factor depends on the type of radionuclide. The radionuclide needs to be known or assumed. The probes cannot serve to determine the nuclide.Please note that the probe 6150AD-17 requires a probe cable which is not included and has to be ordered separately. The probe 6150AD-k already has a short cable fixed to it. It only requires an additional cable if it shall be operated remotely from the 6150AD.Data sheet for both probes|
|The detector of the probe 6150AD-17 is a GM counter with a circular end window. With the protective cap applied this probe can be used for general purpose gamma surveys. With the protective cap removed it is sensitive to alpha, beta, and gamma radiation thereby allowing to monitor surface contamination including wipe surveys. With the protective cap removed the probe is also suited to detect (not to measure quantitatively) low energy photon radiation (e.g., »soft« X-rays) down to energies of a few keV.|
Analog range: 0.1 s-1 – 10k s-1
Digital range: 0.01 s-1 – 9.99k s-1
|The probe 6150AD-k uses a sealed proportional counter which does not require refilling or flushing from external gas reservoirs. Just like the probe 6150AD-17 it is sensitive to alpha, beta, and gamma radiation, however makes surveying larger areas much easier because of the much larger sensitive area. Moreover, it provides an electronic switch to the operating mode »alpha« where only alpha radiation is recognised and detected very sensitively because the background is much lower in this mode. A removable discriminator plate (stainless steel, 1 mm) allows to distinguish between beta and gamma radiation. The handle has an adjustable joint which can be locked to the most convenient orientation. The handle can be extended, e.g. to survey the floor comfortably in an upright position (the extension tubes are optional accessories, see below).|
Analog range: 0.1 s-1 – ~80k s-1
Digital range: 0.01 s-1 – ~80k s-1