NWRI AWWARF APOS S ULTRAVIOLET DISINFECTION GUIDELINES FOR DRINKING WATER AND WATER REUSE

121 CHAPTER 12Putting It All Together All of the elements covered in Chapters 6 through 11 must be combined to forma complete particle counting system. In most cases, the system will be supplied bya single manufacturer, as there is no way to pick and choose the best of what eachhas to offer[r]

pollution. However, where local containment is not provided, or risk assessment indicates thatadditional security is required, for example to contain firewater run-off, which may amount tothousands of cubic metres, then ”remote containment“ systems may be employed. These may be usedin isolati[r]

Instructions for Proper Installation, Operation, and Maintenance of Panelboards Rated 600 Volts or Less, para. 10.3, 10.8.3, 10.8.4  Switchboards—reference Standards Publication ANSI/NEMA PB 2.1-2002, General Instructions for Proper Handling, Installation, Operation and[r]

ranges in cm, so the system does not need the sedimentation unit and this enables easy operation. The biological nitrification is schematically pictured in Figure 2. Wastewater Reuse Disinfection SS removal Nitrification 4Research on the nitrification in our laboratory was cond[r]

picture of a complete filter run. Odd or unexpected increases in counts at a certainpoint in the filter run may be the result of poor sample handling, but if a patternemerges over several filter runs, the data may be considered reliable.Just as in the case of online particle counting, trending the grab[r]

4 to 20 mA current loop signal output. This section is meant to provide a broadoverview of the available options, and the rationale behind each. Technical infor-mation for these approaches are covered in Parts II and III of the book.Determining the best approach for a giv[r]

maintenance personnel are performing the same tasks, and doing so consistently.Brief guidelines for performing each operation should be listed, with a space forrecording any measurements or observations. It may be a good idea to laminatecopies of helpful diagrams from the partic[r]

and have nothing whatsoever to do with the data protocol. All data transmissioninvolves electrical signal levels of some sort. Never assume that two RS-485 deviceswill communicate together. This would be akin to assuming that a lawn mowerengine will work in a Cadillac, because both run on gas[r]

SPECIFICATIONS 77 As mentioned is Section A, the smallest particle that can be reliably measuredmust produce a signal amplitude at least twice that of the noise, or a 2 to 1 signal-to-noise ratio. C. RESOLUTION This term refers to the degree to which an instrument can distinguish betweendifferences[r]

81 CHAPTER 7Particle Sensor Construction A. FLOW CELL The flow cell is a foundation piece of the particle counter sensor. It is generallymade out of aluminum or stainless steel or even plastic. Stainless steel is moreexpensive primarily because it is much harder than aluminum and thus more di[r]

determination, and even more opinions. These decisions relate more specifically toone’s overall approach to particle counting. It is important to remember that particlecounting came into vogue in the drinking water industry a few years ahead of thecomputer technology that[r]

blocking sensor, the photodiode is constantly illuminated, and particles passingthrough the light beam cause a temporary dip in the intensity of the light strikingthe photodiode. The detector circuit inverts the output of the photodiode so that novoltage is output when no particles are presen[r]

6. Make sure the loop has sufficient voltage to drive the input. D. DISCRETE INPUTS Discrete inputs provide a similar value, and are used in the same way as analoginputs, primarily for turnkey type systems. One of the most useful is a backwashvalve position indicator. This is tied to a[r]

147 CHAPTER 16Particle Sensor Construction All the manufacturers of drinking water particle counters provide particle sensorsquite similar in operation and construction. The main variation to be found is in thesize of the flow cell cross-section, and in the mounting of th[r]

wire communications involves transmitting and receiving data over the same pairof wires, while the four-wire arrangement keeps transmission and receiving linesseparate. There is no difference in speed, as the units do not transmit and receive atthe same time. ARTI, Met One, a[r]

the analog inputs are designed to accept 4 to 20 mA signals, while the remainingsix can accept inputs of +5 or +10 VDC full scale. These ranges are selected byadding or removing jumpers on the circuit board (a jumper works like a switch, but L1306/frame/pt03 Page 156 Friday, June 23, 2000 2:15 PM© 2[r]

ARTI and IBR particle counters both employ comparator-type counting elec-tronics. Each provides eight size channels. The size thresholds are set via the digitalinterface. B. POWER SUPPLY All of the units use the newer switching power supplies that provide higherefficiency and will oper[r]

143 CHAPTER 15Specifications Table 15.1 provides a side-by-side comparison of the published specificationsfor the primary instruments discussed in Part III. A. MET ONE PCX The Met One PCX will be marketed exclusively by Hach in North America asthe Hach 2200 PCX. It will be referred to by the Met One[r]