414 Resistivity Help
414R-HP Resistivity Monitor - Help & Support
← View All 414 MonitorsWhat Does My Display Mean?
Status is based on the user-defined setpoint, not the full measurement range. Note: higher resistivity indicates higher water purity.
Troubleshooting
My 414R-HP is showing "OL" - what does that mean?
"OL" on the 414R-HP means the reading is Out of Range. Unlike the 414C and 414TDS, the 414R-HP will always show OL when no sensor is connected, which is normal behavior. Follow these troubleshooting steps:
- Confirm the water is not exceeding 18.18 MΩ·cm - This is the upper limit of the 414R-HP measurement range. If water purity exceeds this value, OL is expected behavior.
- Check for air bubbles or poor sensor contact - Ensure the sensor is fully submerged in constant-flowing water. Tap the probe gently to dislodge air. Install horizontally when possible.
- Verify water temperature is within range - Water must be within 5-50°C for accurate measurement.
- Verify you're using the correct sensor - The 414R-HP uses the CS10S (stainless steel body), not the CTS1 (plastic body). Using the wrong sensor will cause errors.
- Test the CS10S sensor with a multimeter - Check sensor continuity and resistance per expected values. Refer to factory specs or contact support if unsure.
- Check for a component failure - If OL appears with a known-good sensor and flowing water, the monitor may need repair. Contact support.
My 414R-HP is showing "-UL" - what does that mean?
"-UL" means the resistivity reading is below the measurable range of the instrument, below 0.015 MΩ·cm. This typically indicates very low purity water.
- Verify water quality - If the water source is expected to have low resistivity, high conductivity, "-UL" may be normal. A conductivity monitor like the 414C may be more appropriate for that application.
- Confirm you are using the correct sensor - The 414R-HP requires the Hydro-Check labeled CS10S resistivity sensor. Using the wrong sensor will produce incorrect readings.
- Check sensor wiring at TB1 (terminals 7-11) - Verify all connections are secure and match the wiring diagram in the user manual.
- Inspect the sensor for damage or contamination - A fouled, damaged, or improperly installed sensor can produce under-range readings. Clean or replace as needed.
- Contact support - If "-UL" persists with known-good water and a verified sensor, contact orders@hydrocheck.com for further assistance.
Manuals & Instructions
Complete installation, operating, and calibration instructions for the 414R-HP Resistivity Monitor.
Installation
For detailed wiring diagrams and terminal assignments, see the User Manual (PDF).
How It Works
- The CS10S sensor is installed inline in your water process and measures the electrical resistivity of the water.
- The 414R-HP continuously displays the resistivity value in megohm-centimeters (MΩ·cm) on the front panel.
- The instrument uses automatic dual-range measurement to maintain optimal resolution and accuracy across the full scale.
- A linear thermistor network provides automatic temperature compensation to 25°C across a range of 5-50°C, with ±0.1°C temperature accuracy.
- The relay changes state based on the user-defined setpoint: above setpoint = relay is de-energized; below setpoint = relay is energized. A configurable 0-120 second time delay prevents false triggers during startup or rinse-up.
- The relay can drive a 414-RMA Remote Alarm Module, solenoid valve, BMS input, or other external equipment.
Frequently Asked Questions
What is the measurement range of the 414R-HP?
The 414R-HP measures resistivity from 0.015 to 18.18 MΩ·cm, covering applications from lower purity feedwater through high purity and ultra-pure water systems.
The instrument uses automatic dual-range measurement to maintain optimal resolution and accuracy across the full scale. With a theoretical maximum of 18.2 MΩ·cm at 25°C, the 414R-HP is calibrated to 18.18 MΩ·cm within ±1% accuracy.
Does the 414R-HP have temperature compensation?
Yes. The 414R-HP uses a linear thermistor network for automatic temperature compensation to 25°C across a range of 5-50°C. Resistivity accuracy is ±1% of reading, and temperature accuracy is ±0.1°C.
Which sensor does the 414R-HP use?
The 414R-HP uses the CS10S sensor with a stainless steel probe body. This is different from the CTS1 sensor used by the 414C and 414TDS. Make sure you're using the correct sensor, as the cell constant is different between the CS10S and CTS1.
Available in standard cable lengths (10', 25', 50', 100'). Custom lengths may be available upon request.
What accessories do I need for a complete 414R-HP setup?
Minimum required:
- 414R-HP Resistivity Monitor
- CS10S Resistivity Sensor (Hydro-Check labeled)
- PC-110 Power Cable
Optional:
- WMA Wall Mount Adapter
- CM-18 Calibration Module
- 414-RMA Remote Alarm (includes RPC cable)
How do I calibrate the 414R-HP?
The 414R-HP is factory calibrated and typically does not require calibration. If verification or compliance calibration is needed, use the CM-18 Calibration Module.
Connect the CM-18 in place of the sensor and refer to the CM-18 instructions included with the module. Calibration modules come with a Certificate of Conformance.
Can I connect a remote alarm to the 414R-HP?
Yes. The 414R-HP has a built-in SPDT relay on terminal block TB1 (terminals 4-6) that can drive a 414-RMA Remote Alarm Module. The RMA provides visual (green/red LED) and audible alerts at a remote location.
You'll need the 414-RMA module and an RPC cable (available in various lengths).
Documentation
Certificate of Conformance
General Certificate
Download a standard Certificate of Conformance for 414 Resistivity Monitors.
Scan your QR code or contact orders@hydrocheck.com for lot-specific certificates.