CM42 PH/ORP Non-Explosion-Proof Transmitter Manual PART1 Overview
This part is the first section of the non-explosion-proof manual for the CM42 PH/ORP transmitter, mainly covering safety instructions, installation environment, electrical connections, and basic operations. It is suitable for engineering technicians and procurement personnel to quickly master the usage specifications of this instrument in non-hazardous areas. Please read carefully before installation and commissioning.
Download CM42 PH/ORP Chinese Manual.pdf
1. Safety Instructions
The CM42 PH/ORP transmitter is designed for use only in non-explosive hazardous areas. If the application environment contains flammable or explosive gases or dust, an explosion-proof model must be selected. The following are basic safety requirements:
- Installation, wiring, and maintenance must be performed only by qualified professionals.
- Ensure the power supply matches the transmitter nameplate parameters.
- Do not open the housing or perform wiring operations while powered.
- The instrument must be reliably grounded, with a grounding resistance less than 4Ω.
2. Installation Environment and Mechanical Installation
2.1 Environmental Conditions
The transmitter should be installed in a location with low vibration, no corrosive gases, an ambient temperature of -20~60°C, and a relative humidity ≤95%. Avoid direct sunlight and strong thermal radiation.
2.2 Installation Method
Supports wall mounting or pipe mounting, depending on the on-site bracket configuration. Sufficient space must be reserved during installation for wiring and commissioning.
- Confirm that the installation location is free from severe vibration and impact.
- Secure the transmitter to the bracket or panel using M6 bolts.
- Ensure the transmitter is installed vertically or horizontally, with a tilt angle not exceeding 15°.
3. Electrical Connections
Electrical connections must be made strictly according to the wiring diagram. Incorrect wiring may cause instrument damage or inaccurate measurement. All cables should be shielded cables, and the shield layer should be grounded at one end.
3.1 Terminal Definitions
| Terminal No. | Function | Description |
|---|---|---|
| 1 | Power L+ | 24V DC positive |
| 2 | Power M | 24V DC negative/common |
| 3 | PH/ORP Input+ | Connect sensor signal positive |
| 4 | PH/ORP Input- | Connect sensor signal negative |
| 5 | Current Output+ | 4-20mA output positive |
| 6 | Current Output- | 4-20mA output negative |
3.2 Wiring Steps
- Disconnect the power supply and confirm there is no voltage.
- Strip the cable sheath about 7mm to expose the conductors.
- Insert the conductors into the corresponding terminals according to the terminal definitions and tighten the screws.
- Check that all connections are secure, with no short circuits or exposed wires.
- Restore power and observe whether the transmitter powers on normally.
4. Basic Operation and Display
The CM42 transmitter is equipped with an LCD display and four operation buttons, allowing measurement value viewing, calibration, and parameter setting. For specific operation menus, refer to the subsequent sections of the manual.
- Display modes: PH value, ORP value, temperature, and current output.
- Button functions: Up/Down keys switch menus, Enter key enters/saves, Back key exits.
- Default password: 0000 (recommended to change).
5. Precautions and Maintenance
- Regularly check whether cables and terminals are loose or corroded.
- Use a damp cloth to clean the housing; do not use solvents.
- For long-term disuse, disconnect power and store in a dry environment.
- Non-explosion-proof models are strictly prohibited for use in explosive environments.
The above is the main content of PART1 of the CM42 PH/ORP non-explosion-proof manual. Subsequent parts will introduce calibration, troubleshooting, and technical parameters.