Calibration Module Help
Calibration Modules - Help & Support
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Use the CM-18 for 414R-HP resistivity monitors. Use the CM-1K for 414C conductivity and 414TDS monitors.
CM-18
For 414R-HP resistivity monitors when you need verification or calibration confirmation against the 18.00 megohm reference value.
CM-1K
For 414C conductivity monitors and 414TDS monitors when you need verification against the 1000 µS/cm or 666 ppm calibration reference.
CM-18 Calibration Module
For 414R-HP resistivity monitors, including 110VAC, 220VAC, 24VAC, and -520 output models.
How to Use the CM-18
CM-18 Module Verification Values
Use a calibrated multimeter set to Ohms (Ω) to verify the reliability of the CM-18 module. Annual verification is recommended.
| Test Points | Expected Reading | Tolerance |
|---|---|---|
| Pin 7 → Pin 8 | 0.900 MΩ | ± 0.1% |
| Pin 10 → Pin 11 | 13.56 kΩ | ± 0.1% |
CM-18 Troubleshooting
My 414R-HP does not read 18.00 megohms with the CM-18 connected
If the reading is not correct:
- Confirm the sensor is disconnected - The CM-18 must replace the CS10S sensor. Do not connect both at the same time.
- Allow several minutes to stabilize - The meter continuously averages readings, so changes are not instantaneous. Wait for the display to settle before evaluating.
- Check temperature - The temperature display should read 25°C ±0.1°C (24.9–25.1°C). Temperature is not adjustable.
- Adjust using R16 - Use the R16 calibration potentiometer to adjust to 18.00 megohms. Make very small adjustments and allow several minutes between changes.
- Verify CM-18 Calibration Values - Use a multimeter to verify the module test points: Pin 7 to Pin 8 should read 0.900 MΩ, and Pin 10 to Pin 11 should read 13.56 kΩ.
- Inspect Module Condition - Ensure the CM-18 pins are clean, straight, and making proper contact. Replace the module if any physical damage is observed.
"OL" Reading with CM-18 Connected
An "OL" (over limit) reading indicates an open circuit condition.
Check the following:
- Verify installation (TB1: 7–11) - Ensure the CM-18 is fully seated on the correct sensor input terminals.
- Inspect pin contact - Confirm all pins are straight, clean, and making solid contact.
- Verify calibration values - Confirm the module test points read correctly: Pin 7 to Pin 8 should read 0.900 MΩ, and Pin 10 to Pin 11 should read 13.56 kΩ.
If the CM-18 is correctly installed and verified to read the proper resistance, the issue is most likely with the monitor input circuit.
For further assistance, contact: orders@hydrocheck.com.
How the CM-18 Works
- Simulates a CS10S resistivity sensor with a cell constant of 0.05 and an 18.00 megohm water equivalent for 414R-HP verification.
- Constructed with NIST traceable resistors at ±0.01% per MIL-PRF-55182 and factory tested to simulate 18.00 megohm water within ±0.018 megohm.
- It is a sealed module and does not require calibration.
CM-18 FAQ
How often should I verify calibration with the CM-18?
This depends on your quality system requirements. Many facilities verify calibration quarterly or semi-annually. Consult your quality or compliance team for the interval required by your specific standards.
Does the CM-18 expire or need recalibration?
No. The CM-18 is a sealed unit and does not require calibration. If the module is physically damaged or the pins are compromised, contact orders@hydrocheck.com for a replacement.
How long does the calibration process take?
The full calibration process typically takes 10-15 minutes. Most of that time is waiting for the meter's averaging to stabilize between adjustments of R16.
What should the temperature display read?
The temperature should read 25°C ±0.1°C (24.9–25.1°C). Temperature is not adjustable.
CM-1K Calibration Module
For 414C conductivity monitors and 414TDS monitors, including 110VAC, 220VAC, 24VAC, and -520 output models.
How to Use the CM-1K
CM-1K Module Verification Values
Use a calibrated multimeter set to Ohms (Ω) to verify the reliability of the CM-1K module.
| Test Points | Expected Reading | Tolerance |
|---|---|---|
| Pin 7 → Pin 8 | 1.066 kΩ | ± 0.1% |
| Pin 10 → Pin 11 | 13.56 kΩ | ± 0.1% |
The 414C and 414TDS circuits are stable and calibration is not normally required unless needed for QC or certification requirements.
CM-1K Troubleshooting
414C / 414TDS does not read correctly with the CM-1K connected
If the reading is not correct:
- Disconnect the sensor - The CM-1K must replace the CTS1 sensor. Do not connect both at the same time.
- Allow the reading to stabilize - The meter continuously averages readings; allow several minutes for the value to settle.
- Verify temperature - The display should read 25°C ±0.1°C (24.9–25.1°C). Temperature is not adjustable.
- Adjust calibration (R11) - Use the R11 potentiometer to adjust the reading to 1000 µS/cm, or 666 ppm on 414TDS.
- Inspect module condition - Ensure CM-1K pins are clean, straight, and making proper contact.
"OL" Reading with the CM-1K Connected
An "OL" (over limit) reading indicates an open circuit condition.
Check the following:
- Verify installation (TB1: 7–11) - Ensure the CM-1K is properly installed on the correct sensor input terminals.
- Inspect pin contact - Confirm all pins are straight, clean, and making solid contact.
- Verify calibration module resistance values - Use a multimeter to verify the module test points: Pin 7 to Pin 8 should read 1.066 kΩ, and Pin 10 to Pin 11 should read 13.56 kΩ.
If the CM-1K is correctly installed and verified to read the proper value, the issue is most likely with the monitor input circuit.
For further assistance, contact: orders@hydrocheck.com.
How the CM-1K Works
- Simulates a CTS1 conductivity sensor with a cell constant of 1.06, displayed as 1000 µS/cm on 414C and 666 ppm on 414TDS.
- Constructed with NIST traceable resistors at ±0.01% and factory tested to simulate 1000 µS/cm or 666 ppm at 25°C.
- It is a sealed module and does not require calibration.
CM-1K FAQ
Can I use the CM-1K for both the 414C and 414TDS?
Yes. The CM-1K works with both models. The 414C should read 1000 µS/cm and the 414TDS should read 666 ppm.
Does the CM-1K expire or need recalibration?
No. The CM-1K is a sealed unit and does not require calibration. If the module is physically damaged, contact orders@hydrocheck.com for a replacement.
Why does the 414TDS read 666 ppm instead of 1000?
The CM-1K simulates a 1000 µS conductivity signal. The 414TDS converts conductivity to TDS using a standard conversion factor, which yields approximately 666 ppm.
What should the temperature display read?
The temperature should read 25°C ±0.1°C (24.9–25.1°C). Temperature is not adjustable.
Certificate of Conformance
General Certificates
Download standard Certificates of Conformance for calibration modules.
CM-18 Calibration Module
Standard compliance documentation for the resistivity calibration module.
CM-1K Calibration Module
Standard compliance documentation for the conductivity or TDS calibration module.
Traceability Lookup
Enter the lot or serial number exactly as printed on the module label to retrieve traceability and calibration data.
Format guide: CM18-xx-yymmdd, CM18-xxx-yymmdd, or CM18-Bxx-yymmdd.