The A, B,and C coefficients can be converted to α,δ,andβcoefficientsusing
the following formulas:
α= +AB100 δ=−
+
100
100 1
A
B
β=− +
10
100
8C
AB
When the CVD conversiontype is selected, the R0, ALPHA, DELTA, and
BETAcoefficients are displayed on the right portion of the bottom of the dis-
play.Use the UD buttons to scroll through the coefficients. Use the Enter
buttonto edit and save the new setting. Press and hold the Exit button to cancel
to themain display or press the EXIT button to cancel and to move to the next
parameter.On the last parameter, press the Exit button to exit to the menu.
7.2.1.5 RES Conversion
The RES conversiondisplays the measurement as resistance in ohms or K
ohms depending on therange.
When the RES conversiontype is selected, the RANGE and WIRES parameters
are displayedon theright portion of the bottom of the display. The UD but-
tons are used to scrollthrough the parameters. Use the Enter button to change
and savethe new settings. Press and hold the Exit button to cancel to the main
display or press the EXIT button to cancel and to moveto the next parameter.
On the last parameter,press the Exit button to exit the menu.
The RANGE parameteris used to select the appropriateresistance range. For
25 ohm and 100 ohm PRTs,select 100 ohm and for 1000 ohm PRTs, select 10
K ohm.
The WIRES parameter setsthe appropriate number of lead wires from the sen-
sor.This parameter can be set to 2-, 3-, or 4-wires. See Figure 5 on page 24 for
the wiring configuration.
7.2.1.6 Thermistor T(R) Conversion [THERM-T]
The followingSteinhart-Hart equation is used for the thermistor T(R)
conversion:
Tr K A A r A r A r()[ ] [ ln ]=+ + + −
01 2
2
3
31
ln ln
The user-definedparameters for the thermistor T(R) conversion are A0 (A0)
through A3 (A3) as shownon a typical Hart Scientific thermistor calibration re-
port. If A2isnot used, as is the case with some calibrations, A2 should be set to
0.0.
Note: Thermistor coefficientsstated on the thermistor calibration report may be
labeled differently.The best way to identify the coefficients to use with this
type is to match the equation above with the equation giveno n the calibration
report. Also, recognizethat the coefficients for this equation generally have
negativeexponents, e.g. A3: 1.39456E-07.
41
7 Menu Functions
Probe Menu