Indications for Use

The Chlorine Sentinel II is intended for use by hemodialysis professionals as a secondary chlorine device to provide continuous monitoring of Combined Chlorine. It is not intended to replace the primary method of monitoring chlorine as part of the hemodialysis water treatment system. It functions completely independent of the water treatment system does not come into direct contact with feed water used to prepare dialysate.

Overview

The device monitors combined chlorine. Most municipalities use chloramine for disinfection which is a combined chlorine. However, some municipalities still use free chlorine. The Chlorine Sentinel II provides an Ammonia Sulfate feed system as well as bags of Ammonia Sulfate to be used for those municipalities.

The primary-detecting, auto-testing, combined chlorine monitor/analyzer device is designed to provide five types of alerts/outputs:

1. Combined Chlorine at or above a user-defined set point (default 0.02 ppm)
2. Combined Chlorine over a pre-set trigger point (default 0.10 ppm)
3. Chlorine Monitor System Maintenance Required
4. Auto Test Successful
5. Water system Shut-off when Combined Chlorine reaches or is above 0.1 ppm

The chlorine monitor has MODBUS output allowing the chlorine concentration and monitor relay statuses to be integrated into the user water treatment IT system.

The Chlorine Sentinel II is contained in one enclosure. The device is designed to work in the background. Except when the device is in an alarm mode, the only user activity required is to observe that the Auto-Test Successful light is activated at the start of the day and to reset it.

The device requires quarterly periodic maintenance at which time the biotech needs to replace the probe membrane and electrolyte and recalibrate the Probe. For free-chlorine municipalities, check to see if the ammonium sulfate bag needs replacing.

Figure 1: Flow diagram of sample water through the Chlorine Sentinel II

The chlorine probe is fed from sample ports after carbon filters. The connection is located on the drain side of the water treatment test sample port. The sampled water is then discharged down the drain. This assures that with the presence of the check valves and the positive pressure in the feed water that no back-flow is possible from the monitoring system.

The device installation kit provides fittings, tubing and 3-way valve to that the chlorine detecting probe may be fed from after either carbon filter.

Under normal operating conditions, the primary chlorine detection protocols of the water treatment system require testing at the start of the day or the start of each treatment. This secondary chlorine device is designed to provide protection for the patient between primary chlorine device testing. if does not replace the primary chlorine test device.

System Features

• System monitors dissolved combined chlorine. If dissolved free chlorine is present (from city water treatment systems disinfected with free chlorine), the monitor will measure a portion of the free chlorine. Suspended chlorinated solids are not detected.
• Internal Ammonium Sulfate CFP is used with free chlorine disinfected city water.
• When daily start and stop times are set, automatically shuts water off and on.
• System auto-tests daily during down time with results displayed each morning.
• Touch Screen allows all user inputs and outputs required to operate device.
• Allows user-inputted warning set-point for chlorine concentration.
• Design optimized for easy installation and user friendliness.
•  ABS, IP65 water-resistant, V0 fire rated, Controller enclosure.
• Easy installation to sample port drains of existing water treatment system.
• High accuracy — +/- 0.02ppm, repeatability — +/- 0.01ppm.
• Daily automatic self-testing to ensure proper equipment functionality.
• Chlorine analyzer/alarm channel failure alarm.
• System power failure alarm.
• Remote module with alarm enunciator, green Power On indicator, red Chlorine alarm indicator, yellow monitor fail or maintenance needed indicator, and blue Auto-Test Passed indicator.
• MODBUS-RTU allows Combined Chlorine concentration and system diagnostic failures to be sent to external monitoring systems.
• Chlorine Monitor’s large, high contrast, custom LCD display with LED back indicator provides excellent readability in any indicator conditions. The secondary line of display utilizes 5×7 dot matrix characters for clear message display. Two of four measured parameters may be on the display simultaneously.
• High accuracy three-wire Pt1000 temperature input. Temperature element can be user calibrated.
• Security lock feature to prevent unauthorized tampering with analyzer settings. All settings can be viewed while locked, but they cannot be changed.

Device Accuracy

The Chlorine Sentinel™ II uses one of the most accurate chlorine analyzers in the market today*. However, in the application, the device’s accuracy when used in conjunction with a Hach PC for both calibration and reference purposes has a 95% confidence level of +/- 0.025 mg/L. The current ISO 13959:2014 standard limit for dissolved chlorine is 0.1 mg/L of chloramines (combined chlorine); 0.5 mg/L of free chlorine. The implied tolerance is +/- 50% of the least significant digit for both combined and free chlorine. Thus, the Sentinel’s apparent consistency of +/- 0.025 mg/L is well within the Standard’s chlorine tolerance.

In field testing, if the influent water has 100% free chlorine (no combined chlorine) and no BOD demand in its distribution, the Ammonia Sulfate feed system must be used. This system ensures that at least 0.1 mg/L of free chlorine is converted into 0.1 mg/L of combined chlorine in the sample water feed.

*Chlorine Analyzer’s publish performance data

Physician Prescription Required

This medical device has FDA K243898 clearance and requires a physician’s prescription when used as part of a hemodialysis water treatment system.

System Description

The Chlorine Sentinel™ II is a complete system that attaches to the drains of a hemodialysis water treatment system sample port.  It detects total dissolved combined chlorine by two-electrode polarographic membrane direct detection technology. It self-monitors for maintenance required conditions. The device probe can be fed from the sample port drains after the first and second carbon filters (manually switchable).

The enclosure is located in the pre-treatment section of the water room.

The remote light tower is installed in the patient area.

The system has the Chlorine Monitor and Touch Screen on the front of the enclosure.

• Chlorine Monitor shows the chlorine concentration and temperature readings of the sampling water. The chlorine value display is used for calibration and troubleshooting purpose only. The chlorine concentrates values presented on it display are intended to be used for management’s proactive actions, not to make clinical decisions. This device is not a substitute for primary chlorine detection devices.
• Touch Screen shows and contains all the information and activity of the Chlorine Sentinel II as well as the chlorine concentrate log, system event log, maintenance and settings.

Combined Chlorine concentrations detected at or greater than two set-points will activate a chlorine alarm event.

1. Warning Chlorine Set-Point – a warning to alert detection of the chlorine at or above a set point that the user wishes to become aware of. The value can be programed in the Settings Screen of the Touch Screen. The programmable range is 0.01 to 0.09 ppm.
2. Chlorine Over Set-Point – when chlorine concentrate is equal or over the set point at 0.10 ppm. This is the current AAMI-ISO 13959 limit of 0.1 mg/L for combined chlorine and cannot be changed by the user. (At ultra-low concentrations of compounds dissolved in municipal water, 0.1 mg/L is basically the same as 0.1 ppm).

A chlorine concentration equal or above the programmed Warning Chlorine Set-Point

1. the Buzzers pulsing at 5-Hz;
2. the Red Warning Chlorine Set-Point Indicator and Red Light on the Remote pulsing at 5-Hz;

A chlorine concentration equal to or above the Over Set-Point will activate:

1. the Buzzers pulsing at 5-Hz;
2. the Red Chlorine Over Set-Point Indicator and Red Light on the Remote will pulse at 5-Hz;
3. the Water Shut-Off accessory.

These conditions will last for as long as the chlorine concentration is above the set-point or is manually by-passed. The Buzzers can be muted for 3 minutes by pressing the Mute Button on the Home Screen or Maintenance Screen of the Touch Screen. If muted, the buzzers automatically re-alarm after 3 minutes. If by-passed, the Red Chlorine Over Set-Point Indicator will remain on solid (not pulsing). The buzzer will double chirp every 15 minutes as long as the buzzer is by-passed.

After the chlorine detected event is over:

1. The Buzzers and Red Light on the Remote device deactivate.
2. The Red Chlorine Over Set-Point Indicator on Touch Screen deactivates.
3. The Orange Chlorine Detected Indicator alarm indicator on the touch screen and the Yellow Light on the Remote device will pulse at 2-Hz until it is reset by pressing the Reset Button on the Maintenance Screen of the Touch Screen.

A Monitor-related failure will activate the Yellow Chlorine Monitor Fail (Maintenance) highlight on the Touch Screen as well as the Buzzers and Yellow Light on the Remote which will pulse at 2-Hz and remain activated as long as the condition exists. The Buzzers can be muted for 3 minutes by the pressing the Mute Button on the Home or Maintenance Screen on the Touch Screen. The Buzzers can be by-passed on the Maintenance Screen of the Touch Screen.

The Auto Sampling feature of the device is to test the chlorine in the sampling water at the programmed time period on a specific day’s group of the week. When the time falls in the programmed sampling period, the system will automatically sample the water for the programmed duration and frequency.

The Auto Sampling Mode can be overridden by pressing the Manual Sampling Button in the Maintenance Screen. The Manual Sampling Mode will remain activated, for up to 30 minutes at which time the Auto Sampling Mode will return. The Manual Sampling can be de-activated at any time within 30 minutes period by pressing the Manual Sampling Button once more.

The Auto-Test feature of the device is key to confirm that the device is functioning to expectations. The Auto-Test is performed daily – default set at 02:00 AM. When the test if successful, the Blue Light on the Remote and the Blue Auto-Test Successful Indicator on the Touch Screen Home Screen will be solid on advising the user the device is functioning correctly. if the Blue Auto-Test Successful Indicator is not on at the start of the day, the user needs to follow protocol for advising management of the Auto-Test Failure.

The device is designed to work in the background. Other than re-setting the Auto-Test Successful Indicator by pressing the Reset Button on the Home Screen of the Touch Screen, the device requires no user inputs unless a chlorine event or other monitored event is detected.

Users can Manually Test the performance of the device by pressing the Manual Test Button on the Maintenance Screen. When Manual Test is activated, it will sample the water up to 30 minutes. The Manual Test will be user de-activated at any time within 30 minutes period by pressing the Manual Test Button once more.

During the Manual Test procedure, the Buzzers will not be activated. This is to ensure that any patients present at the time of the manual test will not be disturbed by the audio device.