Chemtrac Auto Clean UV254, Owner'S Manual, Page: 28 / 41

Chemtrac UV254 Monitor
– UVM5000 v 2.1
Chemtrac, Inc. 27
14 Maintenance
A standard recommended maintenance schedule is as follows:
Table 7: Maintenance tasks and frequency
14.1
Cleaning F requency and Fluid
Two of the most important factors that affect the analyzer performance are the cleaning fluid used to clean the
flow cell, and how often the flow cell is cleaned (cleaning frequency). The optimum cleaning fluid and cleaning
frequency is dependent on the type of sample water being analyzed.
14.1.1
Cleaning Frequency
The optimum frequency of cleaning is quite variable depending on the amount and type of fouling agents in the
water. This will be dependent on the application and installation point.
The following frequencies may be used as a starting point upon installation.
Wastewater: 4-24 hour frequency
Source Water: 1-7 day frequency
High Purity: 2-4 week frequency
Once in operation, observe the flow cell for signs of fouling prior to the first cleaning cycle. If fouling is present,
increase the cleaning frequency accordingly. The measured data can also be observed for signs of a
“sawtooth”
effect in UVT mode as shown in Figure 14.1. If the sawtooth effect in UVT mode shows a downward trend as
displayed in Figure 14.2, the sensor is drifting, and cleaning frequency must be increased. Figure 14.3 and
Figure 14.4 show the sawtooth pattern in UVA mode (next page).
FREQUENCY TASK
Weekly Visual inspection (display faults, etc.)
Monthly
Validate UVM5000 reading with a Chemtrac UVP1000 Portable Organics Monitor, or equivalent. Recalibrate
if necessary.
12-18 Months Replace UV Lamp and Ribbon Cable
Figure 14.1: UVT Mode - Effective Cleaning
Figure 14.2: UVT Mode - Inadequate Cleaning