Vernier LabPro User Manual
Page 77
Revision Date: 08/02/02
LabPro Technical Manual
77
inside LabPro unit to convert current to voltage; this must be done in the external probe.
3
Default units for the Stainless Steel and TI Temperature sensors is °C.
Channel 11 and 12 (SONIC)
IDENT
Value
1
Sensor Type
Range
15K
Motion detector, meters
0.4 meter to 6 meters
22K
Motion detector, meters
0.4 meter to 6 meters
10K
Motion detector, feet
1.4 feet to 18 feet
1
IDENT values are resistance values in ohms (tolerance ±5%).
Custom Sensors
To create custom-designed sensors or other circuits for the analog input channels or a Digital/sonic input
channel LabPro, you can purchase sensor kits from Vernier Software & Technology.
•
For a custom analog sensor, use the Analog Probe Kit (order code CB-BTA). Each sensor kit
includes a four-foot length of telephone cable with a BTA connector attached to one end. The
other end of the cable is not terminated.
•
For a custom digital sensor, cut a CBL-MDC cable into two pieces to get two lengths of cable
with connectors. (The digital probe kit used with the original CBL (CBL-DNK) will not work with
LabPro.)
Be very careful when designing a custom sensor or circuit. For more accurate operation, do not connect
pins 1 and 6 together on the analog input channels. Pin 1 on the British Telecom-style connector is the pin
farthest from the release lever as shown in the pictures below.
If you design a resistance-type sensor, connect pin 3 (Vres) to pin 6 (Vin-low) (refer to “Connector
Pinouts” below). Connect the resistance to be measured from the junction of these pins to pin 2 (Gnd).
The resistance range for useful measurements is limited from approximately 1 Kohms to 100 Kohms.
When the Operation parameter in Command 1 (page 29) is set to 2, 3, 5, 6, or 7, the data is measured on
the Vin pin (pin 1). The data for all other operations is measured on the Vin-low pin (pin 6).
Note: The most current that can be drained from all four analog channels is 160 mA. This is limited by the
hardware.