Model U-1641 is 250 mm wide. It is a 4-, 6- or 8-pen recorder with intelligent functions.
A digital servo system has been adopted in moving parts. Potentiometers nor drive wires are not used. There is no need for replacement during a periodical check.
Moreover, Model U-1641 comes standard with a 5-inch indicator. All channels can be checked at the same time. Settings for measuring conditions can also be made easily.
A “16TCV1” standard input unit as 1 unit responds to 2 channels. It becomes possible to switch between a DC voltage and a temperature (thermocouple) within the same amplifier. Measurements can be made of voltages and temperatures.


  • u-1641

    Identically shaped large cartridge pens.

    With a recording length of 5km, recordings up to two times the length of our company’s conventional products are possible.Also, because the pen have identical shapes, recording can be done in your favorite color.
  • u-1642

    Automatic pen cap system.

    When the power supply or measurement are turned OFF, the pens are automatically capped to prevent the tip of the pens from drying. This eliminates the troublesome need to place caps when recordings are not being made.
  • u-1643

    Simple pen replacement.

    By pressing the PEN CHANGE switch on the control panel, the pens can be esasily and quickly replaced.
  • u-1644

    Sliding control panel.

    By manually sliding the control panel upwards, confirmation of pen operation, pen replacements and recorder paper replacements can be easily done.
  • u-1645


    This display can display analog waveforms, digital value and various settings as well as monitor all channels simultaneously.
    Further, waveform confirmations can also be displayed in the screen without recording.
  • u-1646

    Also comes with an external remote control function.

    Operations such as chart drive feed, measure ON/OFF and manual printingcan be controlled externally. Futher, parallel operation is possible using a synchronous output.
  • u-1647

    IC memory card included.

    Setting conditions can be saved in eight varieties as well as be easily called and setup.

U-841 Specs

Model U-841-4P (4channel)
U-841-6P (6channel)
U-841-8P (8channel)
External dimensions 438(W)×255(H)×420(D)mm
(Projection things are not included.)
Mass 4P Approx.16.5kg / 6P Approx.18kg / 8P Approx.19.5kg
Use environment
  5to 40℃
35to 80%RH (No dew condensation)
Power supply AC90 to 265V / DC9 to 16V (Option)
Operation method Automatic balancing system
(digital servo system)
Effective recording width 250mm
Type or input unit Plug-in type (2 channels for 1 unit)
Reference point Right end of chart paper
(Left end is also possible by changing the setting.)
Pen interval 4mm
Pen speed Approx. 1600mm/s
Chart speed 10 to 2400mm/min, /h Set in 1mm increments
Accuracy ±0.25% of measurement accuracy and effective recording width including linearity and dead band.
Synchronizer ON, OFF 20 data/mm
Measurement ON/OFF Each channel independent
Resolution of time axis 0.05mm
Sampling speed Max. 4ms
Rapid chart drive 2400mm/min (Reverse rotation is not allowed.)
Accuracy for chart drive ±0.1% when a recording length is 1m over.
Chart end detection Provided. Pens are up and chart drive ends.
Swing-out protection Signal limiter
Paper winding-up Equipped (option)
Superimposed marker Operates by operation switch and external remote controller.
(Link with ON/OFF of synchronizer.)
Auto pen cap Pen is automatically stored at the specified position when power is OFF, measurement is OFF and paper ends.
Display 5″ EL display, 320 x 256 dots
Display mode (1) Range display  Simultaneous display for all channels
(2) Digital measurement value display
(3) Wave
(4) AUX (optional screen)
Scaling Range: -10000 to +10000 Decimal point and unit are set arbitrarily
Withstand voltage Between power supply and chassis (GND)
  : 1500VAC, 1 minute
Between analog input and chassis (GND)
  : 500VAC, 1 minute
Between each an analog input
  : 500VAC, 1 minute
Insulation resistance Between power supply and chassis (GND)
  : 100MΩ or more at 500VDC
Between I/O control and chassis (GND)
  : 20MΩ or more at 250VDC
Between analog input and chassis (GND)
  : 100MΩ or more at 500VDC
Power consumption(TYP.) 4pen At balanced 140W / Max. 250W
6pen At balanced 145W / Max. 250W
8pen At balanced 150W / Max. 250W
Recording paper Roll Recording paper No.2501P50(20m), No.25020P50(50m)
Pen NDL Series All 16 colors
※ Please use genuine products for recording paper. Any failure resulting from any recording paper other than genuine products are out of warranty.

Input unit 16TCV1

Compatible machines U-1641/U-841
Input format Unbalanced,Floating
Input resistance 1MΩ fixed
Signal source resistance Less than 1kΩ
Voltage measuring range 100φV to 100V
Measurement range
-270 to 1000℃
-210 to 1200℃
-270 to 1372℃
-50 to 1767℃
-50 to 1667℃
-270 to 400℃
 100 to 1820℃
Measurement accuracy ±(0.05%(rdg)+0.03%(range)+1φV)
Temperature measurement accuracy ±(0.05%(rdg)+0.5℃) J,K,E,T
±(0.05%(rdg)+1℃) S,R,B
Temperature characteristics
±(0.2φV/℃+0.01%(range) of F.S./℃)
Full scale
±0.01%(range) of F.S./℃
30 minutes after power is applied ±0.5% of F.S.
Noise rejection CMRR:AC(50/60Hz) More than 150dB
NMRR:AC(50/60Hz) More than 50dB
Zero point movement range 0 to ±200%, 0.1% increment
A / D converter Resolution: 16bit
Sampling period: 4ms


Interface unit

This interface is used to connect the U-1641 or U-841 to the host computer and input and output settings and measured values.
Model : 16INF2 RS-232C Interface unit
Model : 16INF3 GP-IB Interface unit

CF card unit

It is a memory unit that records analog data using a CF card. Model : 16MEM1

Recording paper take-up device

Model 16TAK1
Compliance recording paper Roll recording paper [No.25020P50(50m),No.2501P50(20m)]
Operation Single drive (It does not interlock with the recording paper feed mechanism of the main unit.)
Mass Approx.300g
Accessories Recording paper winding bobbin 1
Recording paper holder Left and right each 1

Cart for recorder

Cart for recorder with drawer
Mode : CAR-1

Application example

Application example of U-841

  • Recording of output waveforms from analyzers.
  • Recording of output waveforms from various testers.
  • Various experiments at universities, research laboratories, and enterprises.
  • Recording of exhaust-gas analyses and fuel economy at automakers.


Paints manufacturers record temperature data as quality control data during curing.
Moreover, like paints makers, various manufacturers record and store quality data during product shipment.
One of the reasons for which quality data is recorded and stored by recorders is that a recorder records temperature and voltage signals as waveforms as they are; this makes it difficult to conduct the falsification of data, which recently becomes a problem in various industries, so that the reliability of quality data is enhanced.