Campbell Scientific CR800 and CR850 Measurement and Control Systems User Manual

Page 160

Section 7. Installation

160

1. Send the program in CRBasic example FieldCal Multiplier and Offset

Demonstration Program

(p. 160)

to the CR800.

2. To simulate the flow sensor, place a jumper wire between channels VX1/EX1

and SE6 (3L).

3. Simulate deployment-calibration conditions (output @ 30 l/s = 300 mV, output

@ 10 l/s = 550 mV) in two stages.

a. Set variable SignalmV to 300. Set variable KnownFlow to 30.0.

b. Start the deployment calibration by setting variable CalMode = 1.

When

CalMode increments to 3, set variable SignalmV to 550. Set

variable KnownFlow to 10.

d. Resume the deployment calibration by setting variable CalMode = 4

4. When variable CalMode increments to 6, the deployment calibration is

complete. Calibrated multiplier is -0.08. Calibrated offset is 53.978.

5. To continue this example, simulate a two-stage, 7-day service calibration

wherein both multiplier and offset drift (output @ 30 l/s = 285 mV, output @
10 l/s = 522 mV).

a. Set variable SignalmV to 285. Set variable KnownFlow to 30.0.

b. Start the 7-day, service calibration by setting variable CalMode = 1.

When

CalMode increments to 3, set variable SignalmV to 522. Set

variable KnownFlow to 10.

d. Resume the 7-day service calibration by setting variable CalMode = 4

6. When variable CalMode increments to 6, the 7-day, service calibration is

complete. Calibrated multiplier is -0.0842. Calibrated offset is 53.896.

CRBasic Example 29. FieldCal() Multiplier and Offset Demonstration Program

'Jumper VX1/EX1 to SE6(3L) to simulate a sensor

Public

SignalmV

'Excitation mV output

Public

KnownFlow

'Known water flow

Public

CalMode

'Calibration trigger

Public

Multiplier

'Sensitivity

Public

Offset

'Offset (starts at zero, not changed)

Public

WaterFlow

'Water flow

'Data Storage Output of Calibration Data ─ stored whenever a calibration occurs

DataTable

(CalHist,NewFieldCal,200)

SampleFieldCal

EndTable

BeginProg

Multiplier = 1
Offset = 0

LoadFieldCal

(true)

'Load the CAL File, if possible