Specifications

1. INTRODUCTION
Page 3 © 1998-2007 DH Instruments, a Fluke Company
1.2.2.2 DIFFERENTIAL RPT (MICRORANGE OPTION)
Type
Piezoresistive silicon
Range
0 to 12.5 kPa differential (0 to 1.8 psid)
Resolution
0.14 Pa (0.00002 psi)
Repeatability
± 0.01 % FS
Accuracy
± 0.05 % FS for one year. Taring sequence eliminates zero error.
1.2.3 TEMPERATURE MEASUREMENT SPECIFICATIONS
Specifications are for molbloc mounted Platinum Resistance Thermometers (PRT) combined
with molbox RFM resistance measurement system and temperature calculation.
Range
0 to 40 °C
Accuracy
± 0.05 °C
Resolution
0.01 °C
The molbox RFM internal resistance measurement system is automatically calibrated using
reference 100 and 110 Ω (± 0.01 %) resistors (see Section
5.3).
1.2.4 FLOW MEASUREMENT SPECIFICATIONS
molbox RFM measures the flow through molbloc flow elements. There are two different
types of molblocs, molbloc-L (laminar) (see Section 1.1.1.1) and molbloc-S (sonic) (see
Section 1.1.1.2). Flow measurement specifications, calibration types, ranges and dimensions
are detailed separately for each molbloc type in Section 1.2.4.1 and 1.2.4.2.
1.2.4.1 molbloc-L
The flow range, useable operating pressure and absolute and differential
pressure associated with molbloc-L operation depend on the molbloc used and
its pressure-dependent calibration options (see Section
1.2.4.1.2).
Measurement Update Rate
1 second
Range
0 to molbloc full scale depending on gas and molbloc
pressure dependent calibration type
(see Section 1.2.4.1.2).
Resolution
0.01 % FS
Linearity
± 0.23 % of reading from 10 to 100 % FS,
± 0.023 % FS under 10 % FS
Repeatability
± 0.1 of reading from 10 to 100 % FS,
± 0.01 % FS under 10 % FS
Precision
1
± 0.25 % of reading from 10 to 100 % FS,
± 0.025 % FS under 10 % FS
Stability
2
(1 year)
± 0.15 % of reading from 10 to 100 % FS,
± 0.015 % FS under 10 % FS
Measurement Uncertainty
3
(1 year, N2 and any molbox RFM
supported gas for which the molbloc
in use is calibrated)
± 0.5 % of reading from 10 to 100 % FS,
± 0.05 % FS under 10 % FS
1 Precision: Combined linearity, hysteresis, repeatability.
2 Stability: aximum change in zero and span over specified time period for typical molbox RFM and
molbloc used under typical conditions. As stability can only be predicted, stability for a specific
molbox RFM should be established from experience.
3 Measurement Uncertainty (Accuracy): Maximum deviation of the molbox RFM flow indication from
the true value of the flow through the molbloc including precision, stability and DHI calibration
standard measurement uncertainty.