UK Shipping included; overseas buyers see important note below*


Mini Monitor 900 Series Geiger Counters and Ratemeters, manufactured in the UK by Mini Instruments Ltd (and latterly, Thermo Electron/Scientific) are amongst the most highly-respected radiation  and monitoring instruments in use today.


Over the years Mini Monitors have earned an excellent reputation for reliability, performance, versatility, ease of use and value for money. The 900 series continues to be a popular choice in education, research, medicine, industry and amongst environmentalists and enthusiasts. We stock a wide range of pre-owned instruments, all thoroughly tested, checked and calibrated and where necessary, refurbished to a high standard. Here’s just a brief outline of the key features:
 

  • Fully Tested and Calibrated prior to dispatch
  • Large, logarithmic meter, accurately displays both very low and high levels 
  • Portable & bench operation (mains adaptor or 6 x AA cells)
  • Battery life 300 hrs (typical, 4 hrs use per day)
  • Ease of use – single control for battery check, power on & mute
  • User-settable threshold alarm
  • Battery check
  • Built-in sounder with Mute function
  • Probe cradle and carry handle
  • External DC power & charge socket (charger and batteries not supplied)  
  • Rugged all-metal case
  • Curly probe lead
  • Available with a range of probes
  • Count & Dose rate (cpm/uSv/hr) models in stock 
  • Instruction Manual (see note below) and Calibration Check Certificate Included
  • NEW Optional Waterproof Instrument Carry Case £39.99 (see below) 


                                            First time buyer?  Please Click HERE



NEW! PROTECT YOUR INSTRUMENT

Optional hard waterproof carry case now available for most models *. Protect your instrument from knocks, bumps, water and accidents with a high quality IP67-rated, impact resistant carry case. Features include soft grip handle, holes for padlocks, auto pressure release, stackable design.  Price, including delivery (when purchased with instrument) only £38.99. To add a case to your order simply click the item on the drop-down options list. 

*unsuitable for 900/G and 900/BPGM due to the size of the probes. Larger cases available on request.


 Important Small(ish) Print. Please Read. It's At The Bottom... 


A SELECTION OF OUR CURRENT STOCK

They're Changing All The Time So Please Ask If The Model That You Require Isn't shown

(actual product photos, more pics available on request)

And by the way, we also buy, repair and calibrate Mini Monitor 900s at very favourable rates. We also have a limited supply of spare parts  available, just ask...

900G/G
£380.00 inc UK Shipping (just one remaining) 

Mini Monitor 900/G
Tested & Calibrated Prior To Despatch
Typical Applications: low-level dose-rate monitoring
Probe: Type: MC70 Compensated GM tube, PET connector
Energy Range: 50keV to 1.25MeV
Sensitivities: Gamma & X-Ray (>75kVp)
User-Set Threshold Alarm:   Yes
Cosmetic Condition: A-
Meter Scale: 0 – 75 uSv/hr

900/AR ZP1/2 
£390.00 inc UK shipping

Mini Monitor 900/ZP (ARZP1451)
Tested & Calibrated Prior To Despatch
Typical Applications: monitoring, general detecting
Probe type: Probe: Custom ZP1A 28mm mica end window Compensated GM tube TNC Connectors
Sensitivities: Alpha, Beta, Gamma
User-Set Threshold Alarm:   Yes
Cosmetic Condition: A-



900/72511
£400.00 inc UK shipping

Mini Monitor 900/72511
Tested & Calibrated Prior To Despatch
Typical Applications: general detecting/monitoring
Meter Scale: 0 – 2000cps
Probe: Type: LND 72511 thin-wall GM tube
Energy Range: (manuf. specs)
Sensitivities: Beta, Gamma
User-Set Threshold Alarm:   Yes
Cosmetic Condition: A


900/E (1) NEW LISTING
£460.00 inc. UK shipping

Mini Instruments 900/E (MFG001)
Tested & Calibrated Prior To Despatch
Typical Applications: general detecting/monitoring, measurement, contamination control 
Meter Scale 0 - 2k cps
Probe: type E thin mica end window GM tube 6.0cm² 
Sensitivities: Alpha, Beta, Gamma, X-Ray
Cosmetic Condition: A-
User-Set Threshold Alarm:  Yes
Energy Range: Manuf. specs



900/EL (1) 
£480.00 inc UK shipping

Mini Monitor 900/EL 

Tested & Calibrated Prior To Despatch
Typical Applications: high sensitivity Alpha, Beta, general detecting/contamination control
Meter Scale: 0 – 500cps
Probe: Type: DN212, large window  halogen quenched GM tube
Sensitivities: High Sensitivity Alpha, Beta & Gamma
User-Set Threshold Alarm:   Yes
Cosmetic Condition: B+


900/EP-15 RP**
£500.00 inc UK shipping

Mini Monitor 900/EP-15 RP
Tested & Calibrated Prior To Despatch
Typical Applications: high sensitivity Beta, Gamma general detecting/contamination control
Meter Scale: 0 – 500cps
Probe: Type: Re-tubed EP15, Si 8B, large window  halogen quenched GM tube
Sensitivities: High Sensitivity Beta & Gamma
User-Set Threshold Alarm:   Yes
Cosmetic Condition: A
** NB the probe supplied with this instrument has been fitted with a Si-8B 'pancake' GM tube. It has a 55mm thin mica front window. This is physically more robust than the original LND 7313 tube but with lower alpha sensitivity 



900/EP-15 (6018) NEW LISTING
£530.00 inc UK shipping

Mini Monitor 900/EP-15 (MS3051)
Tested & Calibrated Prior To Despatch
Typical Applications: high sensitivity Beta, Gamma general detecting/contamination control
Meter Scale: 0 – 500cps
Probe: Type: large window  halogen quenched GM tube
Sensitivities: High Sensitivity Beta & Gamma
User-Set Threshold Alarm:   Yes
Cosmetic Condition: A




900/D (1) 

£585.00 inc. UK shipping

Morgan Mini Monitor 900/D (MFG025)
Tested & Calibrated Prior To Despatch
Typical Applications:  contamination and monitoring 
Meter Scale 0.5 - 1000 uSv/hr
Probe: type D thin mica end window compensated GM tube 6.0cm² 
Sensitivities: Alpha, Beta, Gamma, X-Ray
Cosmetic Condition: A
User-Set Threshold Alarm:  Yes
Energy Range: Manuf. specs


900/D (2) NEW LISTING
£585.00 inc. UK shipping

Morgan Mini Monitor 900/D (MFG025)
Tested & Calibrated Prior To Despatch
Typical Applications:  contamination and monitoring 
Meter Scale 0.5 - 1000 uSv/hr
Probe: type D thin mica end window compensated GM tube 6.0cm² 
Sensitivities: Alpha, Beta, Gamma, X-Ray
Cosmetic Condition: A
User-Set Threshold Alarm:  Yes
Energy Range: Manuf. specs





900/AR1288 Scintillator,
£580.00 inc UK shipping

Mini Monitor 900/AR1288
Tested & Calibrated Prior To Despatch
Typical Applications: Gamma detection/contamination control
Meter Scale: 0 – 5kcps
Probe: Type: AR1288 Gamma Scintillation 30mm Nal (TI), Hamamatsu PMT,  TNC connector
Sensitivities: Gamma & X-Ray
User-Set Threshold Alarm:Yes

Cosmetic condition: A+




900/BPGM
£600.00 inc UK shipping

Mini Monitor 900/BPGM
Tested & Calibrated Prior To Despatch
Typical Applications: monitoring, general detecting
Probe type: Probe: Bicron PGM mica-window 'frisker' Pancake Probe,  MHV connector
Sensitivities: Alpha, Beta, Gamma
User-Set Threshold Alarm:   Yes
Cosmetic Condition: A




900/AR-2012 
£625.00 inc UK shipping

Mini Monitor 900/2012
Tested & Calibrated Prior To Despatch
Typical Applications: Gamma detection/contamination control
Meter Scale: 0 – 5kcps
Probe: Type: XP2012 Gamma Scintillation 40mm Nal (Ti), Hamamatsu PMT, TNC connector 
Sensitivities: Gamma & X-Ray
User-Set Threshold Alarm:   Yes
Cosmetic Condition: A





900/AR1705
£675.00 inc UK shipping

Mini Monitor 900/AR1705
Tested & Calibrated Prior To Despatch
Typical Applications: Gamma detection/contamination control
Meter Scale: 0 – 5kcps
Probe: Type: AR1705 Gamma Scintillation 35mm Nal (Ti), Hamamatsu PMT, TNC connector 
Sensitivities: Gamma & X-Ray
User-Set Threshold Alarm:   Yes
Cosmetic Condition: A+

                                                                                                                      




900/CSP
£680.00 inc UK shipping

Mini Monitor 900/CSP
Tested & Calibrated Prior To Despatch
Probe type: Custom Nal scintillation probe, TNC connector
Typical Applications: very low gamma detection,
contamination control
Meter Scale: 0 - 5k cps
Sensitivities: Beta, Gamma & X-Ray
User-Set Threshold Alarm: Yes
Cosmetic Condition: A 



900/42B

OUT OF STOCK 

Mini Instruments 900/42B (MFG015)
Typical Applications: very low gamma detection, contamination control
Meter Scale: 0 – 5k cps
Probe type: 900/42B Berylium window NAl scintillation probe, PET connector
Energy Range: 5keV - 250keV (Beta > 500keV)
Sensitivities: Beta & Gamma
User-Set Threshold Alarm:   Yes
Cosmetic Condition A
* includes FREE waterproof hard carry case 


900/SCI (Scionix 38 B 57 probe)* 

£780.00 inc UK shipping

Tested & Calibrated Prior To Despatch

Probe type: Scionix 38 B 57/1.5M-E1, Nal (Ti)  BNC connector  
Typical Applications: very low gamma detection, contamination control
Meter Scale: 0 – 5k cps
Energy Range: 500keV - 5MeV
Sensitivities: Gamma, X-Ray
User-Set Threshold Alarm:   Yes
Cosmetic Condition: A
Includes FREE waterproof hard carry case 

*Note the Scionix 30 B 57 scintillation probe is physically  similar to the 44A, but with noticeably superior performance, thanks to a larger Nal (Ti) scintillation crystal and Hammatsu photomultiplier tube. 


900/44A (6041)  NEW LISTING
£800.00 inc. UK shipping

Mini Monitor 900 (MFG 016)
Tested & Calibrated Prior To Despatch
Probe type 900/44A Nal (T) PET connector  
Typical Applications: very low gamma detection, contamination control
Meter Scale: 0 – 5k cps
Energy Range: 500keV - 5MeV
Sensitivities: Gamma, X-Ray
User-Set Threshold Alarm:   Yes
Cosmetic Condition: A
* includes FREE waterproof hard carry case 



900/44A (6091)  NEW LISTING
£800.00 inc. UK shipping

Thermo Scientific Mini 900 (MFG 016)
Tested & Calibrated Prior To Despatch
Probe type 900/44A Nal (T) PET connector  
Typical Applications: very low gamma detection, contamination control
Meter Scale: 0 – 5k cps
Energy Range: 500keV - 5MeV
Sensitivities: Gamma, X-Ray
User-Set Threshold Alarm:   Yes
Cosmetic Condition: A
* includes FREE waterproof hard carry case 




 The All-Important Small Print

The Mini Instruments & Thermo Electron/Scientific/Morgan) 900s that we stock were all previously owned but they have generally been very well maintained, regularly calibrated and are in full working order. In addition to any necessary case refurbishments and deep cleaning we carry out a full range of operational checks, including probe supply testing & adjustment, circuit board & cable inspection and pulse-calibration (according to MI protocols and data). This is repeated immediately prior to dispatch.  Some models have fixed probe/ratemeter cables, others have the factory original PET or TNC type connectors. If you have a specific connector requirement we may be able to help, just ask. All models come with an unconditional  6-months guarantee.

Whenever possible we include a copy of the original user manual; we try to ensure that they are  model-specific but in some cases they may be a generic version, covering operation and maintenance.  We also include a battery holder and in most cases, a vented end-window protective cover. Unless noted otherwise they do not come with any other accessories. Instruments are graded according to cosmetic condition from A+ to C-, with A indicating 'as-new' to very good, and C, full working order but somewhat tatty or with more noticeable scratches, dinks and dents, etc. 

And finally... Whilst the instruments that we sell are all in full working order, calibrated, and guaranteed, we do not certify or endorse them for regulatory, health and safety or safety-critical and related applications. 


PLUS, Vital Information For Overseas Buyers:

Hallo, Bonjour, Guten Tag, Ní hao, Namasté, Ahlan bik, Geia!, Shalóm, Hai, Kónnichi wa, Annyeonghaseyo, Szia, Salâm, Witajcie, Privét, Hola, Adaab arz hai, with apologies to anyone we’ve missed…

The prices shown are for UK buyers and inclusive of delivery to mainland UK addresses. Overseas buyers are welcome and should contact us before ordering for shipping options, which vary according to location. Please also note that this item may be prohibited or restricted in some countries.


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Mini Monitor 900 Series Geiger Counters & Ratemeters

  • Product Code: Mini Instruments 900
  • Availability: In Stock
  • £0.00


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