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Diesel Engine Tachometer
GE-2500

The GE-2500 Diesel Engine Tachometer is a novel tachometer that utilizes the fact that the rotational speed of the engine and the rotational speed of the alternator are proportional. By measuring the rotational speed of the alternator, it determines the rotational speed of the engine.
For measuring the rotational speed of alternators, we have developed a dedicated compact detector, the OM-1500. The OM-1500 detects the alternator's leakage flux and measures the rotational speed when connected to the GE-2500. (The OM-1200 can also be used.)

please note:
The GE-2500 may not be able to measure certain engine and motor types, or its measurement range may change depending on the type of engine and motor.
For engines and motors with no prior usage history, please verify them using a demo unit.
For demo units, please contact your nearest branch office.

Features

  • A tachometer that can reliably measure engine speed for any type of engine. Suitable for both diesel and gasoline engines.

  • By utilizing the rotational speed of the alternator, measurement is possible regardless of the engine type or number of cylinders.

  • Features an automatic calibration function. It automatically calculates the ratio of the alternator's rotational speed to that of the engine.

  • To determine the engine's rotational speed from the alternator's rotational speed, you need to perform calibration and determine the rotational ratio before taking measurements.

  • Setting it up is easy. The sensor's mounting position is straightforward, and measurements can be taken even with a rough installation.

  • Measurements can be taken even while the vehicle being measured is in motion or operating.

  • The FFT calculation method allows for measurement even of minute signals.

  • It is highly resistant to noise and enables stable measurements.

The GE-2500 makes measurements that were previously difficult possible.

Comparative data (6-cylinder engine)

Comparative data (6-cylinder engine)

While previous models could measure rotational speeds around idle speed, there was a range where measurements were not possible as the rotational speed increased.
The GE-2500 can perform stable measurements across the entire range.

System Configurations

  • System Configurations

Measurement method

  1. Install a sensor on the alternator.

  2. Calibration is performed to determine the ratio of the alternator's rotational speed to the engine's rotational speed.

  3. Measurement started

  1. STEP 1

    Attach the sensor (OM-1500 or OM-1200) to the alternator.

  1. The sensor is mounted and secured so that it is perpendicular to the alternator's rotation axis.

  2. Connect to the "MAIN" connector on the back panel of the GE-2500.

  • Attach the sensor (OM-1500 or OM-1200) to the alternator.

  1. STEP 2

    Perform calibration and set the alternator and engine rotation speed ratio in the main unit (GE-2500).

  • When using a calibration sensor

  • If setting manually (choose one of three options)

    [Caution] Please keep the engine idling during calibration.

When using a calibration sensor

The rotational speeds of the engine and alternator are measured simultaneously, and the rotational speed ratio is automatically calculated.

  • When using a calibration sensor

Manual configuration (choose from 3 options)

  • Enter the pulley ratio and the number of alternator poles.

Enter the pulley ratio and the number of alternator poles.

  • Enter the rotation ratio (ratio of alternator to engine rotation speed).

Enter the rotation ratio (ratio of alternator to engine rotation speed).

  • Enter the engine speed at idle.

Enter the engine speed at idle.

  1. STEP 3

    After calibration is complete, remove the calibration sensor and start measurements using only the measurement unit (OM-1500 or OM-1200).

The rotational speed ratio values obtained through calibration are automatically saved to the GE-2500 unit. Up to 5 conditions can be saved to the unit.

Specification

Measurement section
Measurement target Diesel engines, gasoline engines (engines without alternators cannot be measured)
Arithmetic method FFT calculation method
Input frequency range 1 kHz, 2 kHz, 5 kHz (Measurement mode MAIN) / 500 Hz (Calibration mode REF)
Measurement accuracy ±2 × Rotational speed resolution [r/min] ±1 count
Rotational speed resolution Frequency range (Hz) ÷ 12800 × 60 ÷ Rotation ratio
Display section
Display Fluorescent display tube
Display update time Choose from 0.2, 0.5, 1, or 2 seconds.
Display resolution 1 r/min, 1 Hz
Measurement display range 20,000 r/min
Input section
Input section 2 ch MAIN (for measurement) REF (for calibration)
Input voltage range ±5 V, ±0.5 V, ±0.05 V
Input connector BNC
Input Coupling AC coupling
Constant current drive power supply 2.2–3.2 mA (REF only)
Analog output section
【REVO】
Output content Output for the calculated rotation speed
Voltage range 0 to FS / 0 to 10 V (Full scale can be set arbitrarily)
Conversion method 12-bit D/A conversion method
Linear number ±0.3% / FS
Output update time Within 200 ms
Load resistance 100 kΩ or more
Output connector BNC
【SIG】
Output content The output signal from the sensor input to MAIN (used by switching between analog output and other inputs).
Load resistance 100 kΩ or more
Output connector BNC
Pulse output section
Output content Outputs a pulse with the frequency of the calculated rotational speed.
[Example: At 6,000 r/min, the duty cycle is 100 Hz Duty 1:1]
Output voltage Hi: +4.5 V or more / Lo: +0.5 V or less (at no load)
Output update time Within 200 ms
Load resistance 100 kΩ or more
Output connector BNC
General specifications
Power supply DC 12 to 24V
Power consumption 8 VA or less
Operating temperature range 0～＋40 ℃
Operating humidity range 20-80% RH (non-condensing)
Storage temperature range -10 to +55°C
Storage humidity range 20-80% RH (non-condensing)
Outline drawings Approximately 144 (W) x 72 (H) x 180 (D) mm (excluding protrusions)

Outline drawings
Weight 2 kg or less
Standard CE Mark compliant, RoHS compliant
Accessories Instruction manuals (3 types, 1 copy each), rubber feet (4 sets)
  • GE-0102 Cigarette Lighter Socket Power Cable, 1.5 m, 1 piece
price  
Option
  • GE-0102 シガーソケット電源ケーブル 1.5 m：
    （GE-0102 は GE-2500本体に付属しています）

*Measurement may not be possible depending on the type of engine or motor. Please check with our demo equipment. For demo equipment, please contact your nearest sales office.
*This product requires that the alternator and engine rotations be synchronized.
*If there is a special alternator or looseness in the belt connecting to the engine, the measurement error may be large and measurement may not be possible.

Related Products

Measurement sensor: Alternator rotation detector... A sensor that detects the rotation speed of the alternator from the leakage magnetic flux.
Model モーター/エンジン回転検出器
OM-1200
 		モーター/エンジン回転検出器
OM-1500
Motor/Engine Rotation Sensor OM-1200

*Cable sold separately
MX-005, MX-010 and others

 Motor/Engine Rotation Sensor OM-1500
Detection method

Electromagnetic induction method
Cable length (Sold separately) 4.9m
Operating temperature range 0～+80 ℃ -10～+100 ℃
Weight Approximately 65g

Approximately 130 g (including cable)
Outline drawings

φ16×54 mm
(Sensor only)
φ16×80 mm
(When the cable is connected)

External dimensions_No.1

φ16×30 mm

External dimensions_No.2
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Cable length: 2 m
Connector: BNC
VP-202
VP-1220 		     
Inquire about this product

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Outline Drawings

最終更新日:2025/09/03