Model 2221

General Purpose Scaler-Ratemeter

Part Number: 48-2065

Features

• Digital Ratemeter with Built-In Scaler
• Dual Analog Meter & Digital LCD Presentation
• Rich Array of Discrete Front Panel Controls
• Single Channel Analysis
• Optional RS-232 Data Output
• Wide Range HV
• Overload Protection

The Model 2221 is a general purpose ratemeter and scaler with an analog display for optimally viewing the count rate and rate of change through all possible four decades of display. It is accompanied by a digital LCD, which can present either the ratemeter data or the scaler counts.

Control functions available include: decade range selection, scaler count time, power on/off, response setting, LCD analog/digital switch, PHA window switch, lamp, audio divide by, audio volume, count zeroing, and scaler start/halt.

The wide range high voltage supply supports a variety of detectors with additional threshold and window settings that facilitate switching between gross counts and the energy band of interest. The instrument housing is cast aluminum with a separate battery compartment and accompanying metal handle. This design delivers industrial robustness, quality, capability, and versatility.

• Specifications
• Meter Faces
• Options
• Documents
• Replacement Parts

• Specifications
• Meter Faces
• Options
• Documents
• Replacement Parts

Specifications

Indicated Use	Field Analysis
Compatible Detectors	GM, Proportional, Scintillation
Ratemeter	Provides a four-decade analog display that is operational any time the instrument is turned on. The ratemeter can also be presented on the accompanying LCD as a digital value when the LCD is switched to the "Dig. Rate"  position.
Scaler	Range from 0 to 999999 counts
Meter Dial	0 - 500 cpm, 50 - 500k cpm logarithmic scale (Meter Faces tab lists other available meter faces)
Digital Display	6-digit LCD display with 1.3 cm (0.5 in.) high digits
LCD Backlight	Activated by LAMP switch
Concurrent Use	Scaler or digital ratemeter is active when not selected, allowing for concurrent use
Timer	Switch selectable divisions of 0.1, 0.5, 1, 2, 5, 10 minutes or CONT (continuous) for manual timing
Controls	Power Switch: On/Off Scale Selector Switch: x1, x10, x100, x1K, LOG Response Switch: Toggles between FAST (4 s) or SLOW (22 s) from 10% to 90% of final reading Meter Zero Pushbutton: To zero meter Audio Volume Knob: Adjusts volume of audio output Audio Divide Switch: Divides audio by either 1, 10, or 100 events per click Meter Lamp Switch: Illuminates meter Window Switch: For selecting between wide open window counts or a narrower setting for viewing a specific energy band Scaler Count Time Selector Switch: 0.1, 0.2, 0.5, 1, 2, 5, or 10 minutes Count Pushbutton: Starts or resets scaler count Count Hold Pushbutton: Stops scaler count and leaves result in the display Scaler/Digital Rate Switch: Selects which mode is presented on the LCD Test Buttons: Battery, High voltage, Threshold, Window Calibration Controls: Recessed screwdriver adjustments with calibration cover
High Voltage	Adjustable from 400 to 2400 V (can be checked on display)
Threshold	Adjustable from 100 to 1000 (can be checked on display)
Window	Adjustable from 0 to 1000 above threshold setting (can be turned on or off)
Gain	Adjustable from 1.5 to 100 mV at a threshold setting of 100
Overload	Senses detector saturation, indicated by “– – – –” on LCD display and meter going to full scale (adjustable depending on detector selected)
Audio	Built-in unimorph speaker with volume control
Audio Jack	For optional headset
Power	4 each “D” cell batteries
Battery Life	Typically 250 hours with alkaline batteries (battery condition can be checked on digital display)
Connector	Series "C" type
Size (H x W x L)	22.9 x 10.9 x 25.4 cm (9 x 4.3 x 10 in.) including handle
Weight	2.5 kg (5.5 lb) including batteries

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Meter Faces

This table lists the most commonly used meter faces. Others are available upon request.

 

Meter Face	Image (click to view larger)	Description	Detectors
202-159		50 - 500 kcpm 0 - 500 cpm	Any
202-467		0 - 10 kcps 0 - 10 cps	Any
202-930		1 - 10 kcps 0 - 10 cps 0 - 0.666 µR/hr	Model 44-10

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Options

Option	Description	Part Number
RS-232 Output Option SMA Connector	This option facilitates exporting data to be read as output to a computer or serial printer from either the ratemeter or scaler reading.	4261-148
RS-232 Output Option 9-Pin D-Sub Connector	This option facilitates exporting data to be read as output to a computer or serial printer from either the ratemeter or scaler reading.	4261-184
Model 243	Shielded well gamma sample counter head.	47-1621
Sample Planchets	Set of 500 aluminum or stainless steel sample planchets.	Depends on material
Headphone Jack	Adds headphone jack to instrument.	4464-464
Stereo/Mono Headphones	Adjustable stereo/mono headphones.	22-9313
Stick-On Check Source Holder	Adhesive check source holder that attaches to instrument housing.	4464-473

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Documents

• Data Sheet
• Product Manual

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Replacement Parts

Description	Part Number
Meter Bezel	4261-111
Handle	4334-020

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