Operation; Pressure Sensors - Ametek Crystal HPC51 Operation Manual

Intrinsically safe handheld pressure calibrator

Table of Contents

Operation

PRESSURE SENSORS

The HPC50 Series is equipped with one or two pressure sensors. In addition, one or two intrinsically safe APMi (Advanced Pressure Module) or ATMi (Advanced

Temperature Module) external modules may also be used. For information on the Crystal external modules, please refer to

Be sure to choose the proper sensor based on working pressures and accuracy.

WARNINGS: The following warnings apply to any sensor used with the HPC50 — whether internal or external:

•

Pressure sensors may be damaged and/or personal injury may occur due to improper application of pressure. Please refer to the

Ranges and Resolutions table

for information on overpressure ratings.

•

The calibrator will display

+ OL

when an inappropriate pressure is applied. If

to prevent damage or possible personal injury.

Note:

+ OL

is displayed when the pressure exceeds 110% of the nominal range of the sensor.

Pressure Connection

Crystal CPF System: Medium Pressure Female (MPF) (1/4" medium pressure tube system with 7/16-20 threads). See our

CPF o-ring size and material: AS568A-012, Viton 80 durometer (P/N 3981).

For most applications CPF Fittings can be hand tightened (no tools required). Wrench tightening is recommended (to achieve a metal to metal cone seal) for

applications where chemical compatibility of the process fluid and the o-ring are a concern. Cone seals require only moderate assembly torque to seal up to

10 000 PSI (700 bar). We recommend a tightening torque of 120 in-lbs ±20 in-lbs for our CPF fittings. Please note this is only a fraction of the typical torque

required to seal a 1/4" NPT fitting. If a torque wrench isn't practical to use, the fittings can be assembled as follows: Hand tighten fitting fully

until the cone has bottomed out, then tighten an additional 20° using a hex wrench. Apply a small amount of media-compatible lubricant to the gland

threads and male cone to increase fitting life, reduce the likelihood of galling, and promote sealing.

CAUTION: To achieve CPF maximum allowable working pressures no o-ring substitutions are allowed. See our CPF brochure and

CES-003 CPF Safety Guide available from the website at

Measuring Vacuum

All versions of the HPC50 can be used to measure moderate vacuum.

When measuring pressure less than ambient barometric conditions, a minus (-) sign will appear.

CAUTION: The HPC50 is not recommended for continuous use at high vacuum.

+ OL

is displayed, the pressure should be reduced or vented immediately

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