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TREK Model 212HS Q/m Test System

Trek's Model 212HS Charge-to-Mass Ratio System is a portable Q/m analyzer that utilizes the “draw-off” toner transfer method to provide repeatable, highly accurate toner/powder charge measurements. Due to its small size and weight, the instrument is highly portable, making it an excellent choice for use directly on the production line or in the laboratory.

The TREK Model 212HS system employs a unique specimen separation and transfer technique that avoids the creation of measurement errors due to the undesired additional charging of test specimens sometimes caused by the rapid air movement associated with "blow-off" type measurement systems. The unit is configured as a separate main indicator unit, a plug-in sample cell unit, and a plug-in absorption nozzle unit to allow for different configurations in response to various user applications. A two position switch selects pump strength for normal or high application needs, such as for measuring charge on single component toners (when stronger suction is required).

All measurement data is displayed on a front panel read-out and is available as analog voltage data on output 1 (absorption nozzle data) and output 2 (sample cell data) rear panel BNC connectors. Data can be temporarily stored to on-board system memory with the push of a button and then saved more permanently to a personal computer.

* Measuring toner mass requires the use of a weigh scale which is not included in the Charge-to-Mass Ratio Test System.


Show/Hide Product Technical Information


Measurement Range
0.000 to ±1.999 microcoulombs.
(other ranges available as options)

Measurement Resolution
0.001 mC (1 nC).

Monitor Output
   Better than 0.2% of full scale.
   DPM Display Output
   ±0.25% of full scale.

Vacuum Pressure
10 kPa.

Normal Absorption (Nozzle Unit)
50 Hz: 6.0 to 6.5L / minute
60 Hz: 6.0L / minute

Maximum Absorption (Nozzle Unit)
50Hz: 11.6L / minute
60 Hz: 10.6L / minute


Main Indicator Unit


280mm H x 220mm W x 280mm D
(11.0² H x 9.0² W x 11.0² D).
8 kg (18 lb).
Power Requirements
Factory set for one of three ranges:
100 V AC, 115 V AC, or 230 V AC at 48 to 63 Hz (all ±10%)

Cell Case Unit

45mm H x 70mm W x 54mm D
(1.70” H x 2.75” W x 2.13” D).
150 g (5.29 oz).
Stainless Steel Mesh (supplied)
Plain Woven No. 400
28.7 mm diameter,33 mm opening,
27.8% opening ratio.

Absorption Nozzle Unit

1700 mm L, including tube.
(66.93² L, including tube).
350 g (12.34 oz).
Operating Conditions
5°C to 35°C.


Front Panel Features

Display Operation Touch Screen
Displays measured values and saved data. The Reset functions and the Pump ON/OFF function are accessed through this screen.

Reset Function 1
Used to reset the coulombmeter for the Absorption Nozzle Unit to zero.

Reset Function 2
Used to reset the coulombmeter for the Sample Cell Case to zero.

Display Function 1
A display to indicate the charge transfer to the Faraday cage in the Absorption Nozzle Unit.

Display Function 2
A display to indicate the charge transfer from the Faraday cage in the Sample Cell Case.

Power Switch
Power ON/OFF

USB Connector
Two (2) USB ports (one active; one reserved for future use) to connect the main unit to a personal computer.

Rear Panel Features
Fuse Holder
Houses the AC line fuse (250V/3A).
AC Input
Connects the AC line cord that provides AC power to the unit.

Ground Terminal
Must be connected to a common ground point.

Flow Rate Adjustment
Adjusts air flow rate on the vacuum suction.

Air Outlet
Expels internal air pump exhaust.

Analog Output Connector 1
BNC connection to output the analog data of channel 1 to an oscilloscope or other external device. Scale factor is 1 V/1µC.

Analog Output Connector 2
BNC connection to output the analog data of channel 2 to an oscilloscope or other external device. Scale factor is 1 V/1µC.


Side Panel Features

Air Inlet
Receptacle used to connect the socket of the absorption needle unit.

Analog Input Connector 1
Accepts the BNC connector from the absorption needle unit.

Analog Input Connector 2
Accepts the BNC connector from the cell case unit.

Switch Input Connector
Receptacle used to connect the switch connector from the absorption needle unit.

Nozzle Holder
Receptacle used to hold the nozzle casing of the absorption nozzle unit.

Cell Case Holder
Used to hold the cell case unit.


Accessories Supplied

  • Screw driver, plastic wrench, extra silicon tubes, extra silicon tubes, Type #2 filter papers (H6001), extra No. 400 mesh screens, line cord, and manual.
  • Nozzle Filter Section
    Nozzle Filter set, Filter Case, Nozzle Hose, Filter Case Stopper, and silicon tubes.
  • Cell Case Section
    Sample Cell Case (with Cell Case, Cell Case Stand and Cell Case Stopper), and No. 400 stainless steel mesh screens.

Accessories Available

  • Carrying case.


TREK, INC. certifies that every Model 210HS-3 Q/m Test system is tested and calibrated to specifications using measurement equipment traceable to the National Institute of Standards and Technology or traceable to consensus standards.

All specifications are subject to change

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