DUAL IN-LINE TDS METER INSTALLATION
Dual In-Line TDS Meter displays Total Dissolved Solids (TDS) measured in Parts Per Million (PPM) of Feed Water
(IN) and Purified Water (OUT). Using Dual TDS Meter on weekly basis to measure TDS of Feed Water vs. Purified
Water, RO System users can quickly verify membrane performance of at least 75% TDS removal with following Percent
Removal (Rejection) calculation:
Example Calculation:
TDS Numeric Readings:
% Rejection Rate Calculation:
Tap (In) TDS = 260 ppm
= [(260 - 20) / 260] x 100
RO (Out) TDS = 20 ppm
= [240/260] x 100
= (.923) x 100
= 92.3% Rejection Rate
NOTE: RO membrane should be changed if % Rejection Rate falls below 75%
1.
To mount TDS Meter, remove adhesive backing on Velcro strips and press meter box against flat, vertical surface.
2.
Splice Feed Water "IN" Probe after In-Line Ball Valve into ¼" orange feed supply tube.
3.
Insert 3/8" Blue Faucet Tube originating from the RO system into Pure Water "OUT" Probe.
4.
Insert 5” length of 3/8" blue tubing into opposite end of Pure Water "OUT" Probe.
5.
Apply 3/8" x 1/4" Reducer Union.
6.
Insert 6" length 1/4” white tubing into 3/8" x 1/4" Reducer Union, then apply dispenser tee.
7.
Insert 1/4” Blue Faucet Feed Tube (currently trimmed to 6" length) into other end of dispenser Tee.
NOTE: Orientation of either Probe is not critical.
Direction of flow through either Probe is not specific.
13
Figure 8
% Rejection =
Tap TDS - RO TDS
Tap TDS
x 100
PPM
ON/OFF
DUAL TDS METER
OUT
IN
"IN" Probe
1/4X1/4X1/4
3/8X3/8X1/4
"Out" Probe
"Out" Probe
3/8X3/8X1/4
To Dispenser(s)
1/4" Tube
3/8 X 1/4
Reducing
IN
OUT
Water Supply
To Cold
Stud
Faucet
Union
Tube From
3/8" Faucet
Feed Supply
Tube To
RO Manifold
RO Manifold
(Included)
