Hach 910, Instrument Manual

Page: 37 / 54

Section 4
Page 35
MeterInstallation.fm
Connecting Sensors to the Flow Meter
Figure 15 Velocity Receptacle Pins
4.3.3 Rain Gauge
An optional Hach tipping bucket rain gauge may be connected to the 'RAIN
GA.' connector of Model 920 and 930 flow meters. Each tip of the bucket in
the rain gauge transmits a dry contact closure to the flow meter. Each dry
contact closure represents 0.01" (0.0254 cm) of rainfall. A constant dc voltage
is supplied on Pin C of the rain gauge receptacle. The dry contact closure in
the rain gauge returns a voltage pulse into Pin A with each tip.
Figure 16 and Table 8 describe the pins on all of the rain gauge receptacles.
Figure 16 Rain Gauge Receptacle Pins
B A H
C
J K G
D E F
Table 7 Velocity Receptacle Pin Description
Pin Letter Description Wire Color
A +12 V dc Red
B Ground Green
C Velocity receive (ground) B/W shield
D Velocity receive (+) B/W center
E Velocity transmit (ground) Black shield
F Velocity transmit (+) Black center
G Depth (-) Black
H Depth (+) White
J
Not used NA
K
A
B
C
D
E
F
Table 8 Rain Gauge Receptacle Pin Description
Pin Letter*
* Pins B, D, E and F are not used in the rain gauge connector.
Description
A Tip Signal / 0.01" (2.54 cm) of rainfall
C Source Voltage